My relationship with Nathan was having some thermostat problems. In other words, it was hot. Then it was cold. Then it warmed up again. I guess this was the no man’s land of adult relationships. Here I thought college guys were frustrating? Ha!

Had I scared him? Enlightened him? Rocked his world? I didn’t hold out much hope that I’d made some kind of emotional breakthrough with him. He was a successful, driven man; he didn’t get to where he was by being malleable and afraid.

On the other hand, something compelling had awakened in me. For the first time I felt more secure in my body and femininity. That little power exchange I’d experimented with had resulted in a fiendish need to try new things. New, sexy things.

Shower sex was harder than I thought. Bathtub sex was easier. Being bent over the couch was hot, but my first attempt at sixty-nine ended up with me kneeing him in the face. He sported a black eye for the next week.

“Where is your underwear?” Nathan started with surprise as he explored under my skirt when we met for dinner one day at a dark little restaurant. The horseshoe booth hid a multitude of sins.

“I didn’t wear any today,” I replied, biting my lip as he circled my clit under the table. He knew just where to touch me, exactly where my body would tremble and quake uncontrollably. I was still learning those areas on his body.

“You’re a naughty girl, Zoe.”

I fluttered my eyelashes at him. “Are you going to take me over your knee?”

Worse. With an evil grin, he ruthlessly pinched my clit between his thumb and forefinger and then left me hanging on the edge of climax for the rest of the meal. He sat far enough away from me that I couldn’t touch him. I could only fidget at his nearness. My upper thighs were slick with my arousal, and no panties to catch it, when we headed home.

Before we walked into the apartment, I kissed him shyly and thanked him for dinner, like we were on a first date. It was… sweet. Then he opened the door and frog-marched me into the living room, where he bent me over the back of the couch and flung my skirt up.

Exposed and unsteady, I panted softly and waited. My nerve endings fizzled as I heard the sound of his zipper. As he folded over me, his chest heaving against my back, he whispered, “I can’t stop myself. What are you doing to me?”

It took him approximately ten seconds to seat his cock deep in me, and less than another ten seconds for me to cry out as my delayed orgasm finally ripped through me.

The next day my period started and I lived in granny panties for a few days. A part of me was relieved I wasn’t pregnant, not that I thought Nathan had been lying to me about the vasectomy.

Nathan didn’t appear to notice my time out, which mystified me. I’d thought he would want me every day, but three, then four days went by without either of us making a pass at the other. Was it his move or mine? It was like a game of sexual chess—and I could barely play checkers. By the time Aunt Flo left town, I was missing him fiercely.

“What do you say?” I swung the crop from my hand one evening. “Wanna teach me some new tricks?”

His shrug was infuriatingly noncommittal. “Are you an old dog?” he asked with a chuckle.

“Well, if the leash fits…”

He finally looked up from his phone, over which his thumbs had been flying. His eyes narrowed at me. “I’m not going to collar you, Zoe.”

Awww. Part of me was disappointed. Another part of me was very, very damp at even the suggestion. The truth was that despite my curiosity about all this, the majority of my education in this area so far was from books and a few websites. And I knew better than to believe everything I read online.

Nathan’s gaze followed the line of the crop in my hand up to my bare arm, and he sat upright on the couch as he took in the pink bra and panty set I wore. “Are you trying to seduce me?”

Frankly, I didn’t think I had to try to seduce him. But apparently big brother had an attack of conscience or worse—maybe he didn’t want me anymore. Burying all my nerves and gathering all the confidence my pretty lingerie gave me, I moved to behind the couch where he sat. If he was going to reject me, I didn’t want to see his face while he did it.

Bending over the back of the couch, I nuzzled the curve between his neck and shoulder. It was, without a doubt, my favorite part of his body—his smell, his taste, the way his stubble rasped against my lips at the end of the day. At that moment, the way he bit his lip and tried to suppress his own small shiver gave me more of a thrill than any tingle in my girl parts.

I wanted to affect him as much as he affected me, but I figured that was naïve and foolish. He was rich, gorgeous, and wicked. Yeah, we were not on a level playing field.

“Would you like me to seduce you?” I whispered in his ear. With my other hand, I reached the crop down his arm to tickle his arm. He was still wearing a button-up shirt, but it was rolled up to expose his strong, tanned wrists.

“Be careful what you wish for, Zoe.” He bent his wrist and grabbed the crop in his fist, tugging my arm along with it. My head knocked against his lightly.

“Oof!”

The man was an expert at putting me off-balance—emotionally, psychologically, and now literally. He spun around to pull me over the smooth leather back of the couch and on to his hard lap.

“What was that about new tricks?” he murmured against my lips. I was stretched out over him, almost lying on top of him. He made one hell of a mattress.

I was too close not to kiss him. It was as inevitable as my next breath. As his tongue glided against mine, he dragged the end of the crop up the back of my calf.

“You want to try this?”

I nodded, my lips seeking his again. His erection pressed into my belly. I braced myself up a little with one hand and shoved the other one between us to pull his shirt out of his waistband.

Need more. More skin.

My breath hitched as I touched the crisp hairs below his navel. Happy trail, indeed. Ecstasy trail was more like it. As I toyed with the button on his pants to get closer to the hard promise underneath, he snapped the crop against the back of my knee.

“Uh uh uh,” he chided.

I froze at the challenge in his eyes. The tender flesh behind my knee stung from his little flick of reprimand, making me wonder exactly what he wanted to do to me.

For all my curiosity, I was smart enough to be a little afraid. The spanking was intense enough, but I didn’t know if I could handle a riding crop or a flogger. There was something… more violent about using a toy like that, more detached—like the difference between swatting a misbehaving child and whipping a wild animal.

This wasn’t a game we were playing anymore. This was a kink he had experience with, and I did not. Not in a million years did I believe he would harm me, but it would be just as easy to flay my heart into ribbons.

“What is it?” He’d noticed the shift in my mood.

I pulled my hand away from the ridges of his abs and began to push myself up and off of him. It was hard to think logically when I was this close to him.

Escape would not be so simple, however.

He tossed the crop over the back of the couch and let it clatter to the floor. Then he clamped his hands over my ass, holding me to him. “No. Stay.”

I rolled my eyes. “Arf.” I resisted the urge to stick my tongue out and pant comically.

“So funny,” he muttered. “Maybe I will collar you after all.”

His little joke nearly stopped my heart. With one hand planted on my ass, he drew the other up my spine to tangle in the hair at the nape of my neck. Still, he held me to him, no space between our bodies.

My legs parted, my knees finding purchase on either side of his hips so I didn’t fall. The position, though steadying, underscored the strength of his arousal beneath me.

“Zoe? Tell me what you’re thinking.”

“I don’t know.”

“Don’t know what?”

“I don’t know what I’m thinking, what I’m doing. What we’re doing. My friends think that hooking up with you is super hot, and super stupid.” The disappointment on Tom’s face when Halle let it out still rankled me.

“You told your friends?” Nathan’s grip on me tightened as his voice iced over.

“Sort of. Halle kind of guessed. Was I not supposed to? Is it a secret?”

He pushed himself up to sitting, sliding me off his lap to the floor like I was a family pet that was shedding on him. “God, you’re so fucking young.”

The way he shook his head lit a fuse in me, inflaming all my anxieties.

“That’s it, isn’t it? I’m too young for you to do anything but just play with me. I’m a sex doll. Not worthy of a real relationship, right?”

“Zoe, if I wanted a sex doll I’d get one.” He rose from the couch, efficiently shoving his shirt back into his pants.

And just like that, I went from aroused to anxious to angry. I stood up, wishing his stupid minimalist couch had a throw pillow for me to chuck at his head. Instead I had to settle for throwing him dirty looks.

“You’re so fucking patronizing sometimes, Nathan! Just because you’re older, richer, more experienced or whatever, doesn’t mean you need to be so goddamn condescending!”

He opened his mouth, then pressed his lips together tightly. Whatever he’d wanted to say, he refrained. It was the same expression he’d had when I tagged along to that apartment showing with that Lucas dude. Nathan had turned into a stammering mess just trying to introduce me. It had been humiliating. My deepest fears were now spilling out of me, like so much vomit after my rollercoaster ride of sexual self-discovery.

“Are you ashamed of me?” I asked him, feeling smaller just by posing the question. Now I really wished there was a pillow I could hug to myself.

“Is that what your friends think?”

“No!” I yelled. “I don’t know. I don’t talk about you like that.” I tried not to talk about him at all. Whatever we had begun was ours, private and new.

“You make me feel like an idiot for wanting you. You know that?” Now it was my turn to clamp my lips together, as I sensed a telltale prickling in my nose. I was going to start crying soon. I hated crying.

“You’re not an idiot.”

“This—” I waved my hand between us. “This mood swing stuff is not sexy. It’s not fun. This is real punishment, not knowing what you want with me.”

What were we? Did we have a label, an end game, anything? I was his, but was he mine? Could I take him to an office party? Could I kiss him in public?

I hugged my knees to my chest on the couch, the white leather cool on my skin. Nathan walked over to the kitchen area, tugging at his hair and letting out a handful of frustrated huffing noises.

He hid behind the island, watching me carefully and growling occasionally. Now who was acting like a puppy? Unable to stand the silent scrutiny anymore, I hopped off the couch to go to my room. At the very least, putting clothes on might help repair my dignity.

“Zoe.”

I stopped, hating myself for my instant reaction to his command. Woof.

“I hate all this… talking.” He sighed heavily. “Do you want a—what did you call it? A real relationship?”

I turned around to face him. “I’m not sure,” I told him honestly. “Do you?” Did he even know what one was? I doubted it.

The light above the island carved shadows into his face, so that his expression was hard to read. His hands spread out over the stone top, his thumbs tapping impatiently against the hard surface.

“You’re not an idiot for wanting me,” he assured me. “In fact, I’d be a little shocked if you didn’t.”

“Not helping with the patronizing, Nathan.”

“Okay, let me ask you this. What if we met at our parents’ wedding? What if I’d actually gone, met you, asked you to dance, and then tried to fuck you in the coat check room later on?”

The hypothetical picture he painted made me swallow hard, heat sparking through my lower body. “So? So what?” I asked weakly.

“Do you think for one second that anybody there would be happy for us? Or would they be shocked and disapprove because we’re related?”

“Only technically,” I reminded him. “We’re consenting adults.”

He stared at the island, his hair burnished into bronze by the pendant light above him. “Maybe I’m an idiot for wanting you.”

Oh my god. He was ashamed of me.

“Shit, that’s not how I meant it. The look on your face—fuck. Stop it!”

He bolted out from behind the island and stomped toward me with his hands up, as though he was going to physically wipe my expression clean. When he was a foot away from me, I stumbled back. He stopped in his tracks, lowering his hands to his sides.

“Zoe, do you know how many women I’ve had in my bed?”

I couldn’t take much more of this conversation. For the first time, I put my hand up to silence him. “Nathan, please—”

“None. Zero. Fucking nobody.”

“Okay,” he amended, “maybe in the Den of Iniquity.” His air quotes made me smile, even though we were talking about him banging somebody in my now bedroom. Ugh. “But that was just for fun.”

“I’m not fun?”

“Sweetheart, you are work. What I’m trying to say is that you are the first woman to sleep in my bed. To have her girly shit in my bathroom and her shoes in my closet.”

“Technically, they’re still under the be—”

His hand covered my mouth. “This may be a terrible idea,” he said. “And I’m usually known for being a pretty smart guy. But do not, for one single second, think that I don’t want you. I do. I fucking ache for you, Zoe.”

He shook his head, frowning as he continued. “It’s shameful. It’s weak and embarrassing and I’m out of my mind for my hot young stepsister who tastes like candy and who has the thermal self-regulation of a lizard.”

I wrapped my arms around him, his warmth seeping into my bones and soothing me. He did want me, more than he’d probably ever wanted someone before. This was as new to him as it was to me. We both had internships this summer, basically. He was just learning how to adult the same way I was. That was enough for now.