“And then what happened?” Sabrina’s green eyes are nearly as big around as my fists, and I’m pretty sure she’s going to fall off her stationary bike if she leans any closer to mine.

But considering this spin class is being held in the shallow end of the YMCA pool, the most damage my sister would sustain is a soaked sports bra and some smeared eyeliner. Bree may have given up modeling, but she’s still not about to step foot outside her apartment without eyeliner and mascara, even if she’s only headed to the gym.

“Jesus, woman, spill it!” she hisses. “Don’t keep me in suspense.”

Casting a furtive glance toward the front of the class, where our no-nonsense underwater bicycling teacher is shouting encouragement over the music, urging us to “push through the resistance, little fishies, you’ve got this!” I shake my head. “Then nothing happened. I froze. I freaked out. I bailed.”

Sabrina’s pert nose wrinkles. “So you ran out of your own apartment in the middle of the night?”

I roll my eyes. “No, I faked an emergency and hid in the bathroom until Will left.”

“You faked an…” Sabrina breaks off with a snort-giggle. “Oh my God, you didn’t. Tell me you didn’t fake a case of the green apple splatters to avoid sex lessons.”

“I couldn’t think of anything else,” I say defensively, scowling as Bree begins laughing so hard her feet slip off the pedals. “What? It was the first thing that popped into my head. Will knows I’m allergic to eggs, and I knew I had frozen custard in the freezer from the last time you came over, so…”

Sabrina laughs harder, her eyes squeezing shut as she braces her forearms on her handlebars. “Well, that’s one way to kill the mood.”

“Will and I lived together for five years, Bree, it’s not like he’s laboring under the impression that I never do number two.”

Bree snorts, coughs, and ends up choking on her next round of hysterical giggles, finally drawing the attention of Kyle, our instructor.

“Focus, girls!” he shouts, snapping his fingers over his head. “Mermaids don’t earn their legs by slacking off halfway to the finish line.”

“Mermaids…” Sabrina gasps for air as a fresh wave of laughter makes her shoulders shake. “How is a mermaid going to ride a bicycle?”

“Let’s push this, ladies!” Kyle shouts, ignoring Sabrina as he stands on his pedals, lifting his purple-speedo-covered bottom out of the water. “Ramp up your resistance and let’s go, go, go!”

Attempting to pull herself together, Sabrina brings her hands back into position, pedaling diligently even as soft snorts of laughter continue to escape. A part of me wants to reach over and pinch her thigh under the water, the way I would have when we were kids and she had one of her epic giggle fits, but the logical part of me realizes that she’s simply too young to understand.

I’m only two years older than her twenty-one, but the things I went through as a kid made me grow up fast. And I was in a serious relationship with a full-grown man for five years. I understand that it’s impossible to maintain a sense of girlish mystery when you’re sharing a home—and a bathroom—with the one you love.

Will held my hair back when I vomited on my twenty-first birthday—even two mai tais were one too many for this lightweight—gave me a bath when I had the flu and was too weak to drag my body out of bed, and ran to the pharmacy when I would start my period and realize I was out of tampons. He knows I once had a case of athlete’s foot that lasted two months, that I smell terrible after a hard workout, and that eating anything with eggs in it is going to send me racing for the bathroom.

He knows every flawed, human, stinky, not-perfectly-feminine part of me, and he still loved me to bits and pieces anyway.

He still loves me anyway…

I could feel it last night. Love was there in the room, simmering beneath the sexual tension that thickened the air, making every breath feel loaded with dangerous possibilities.

Dangerous, but exciting, too…

That’s what had scared me the most—how much I liked the thought of taking Lesson One even further, of stripping off my clothes and letting Will do whatever wicked things he wanted to do to my body. He was right—there was a reason I’d skipped the bra as I was getting dressed for a night in. I hadn’t realized it at the time, but my subconscious knew what it wanted.

After a year of celibacy, my subconscious is sick of nights spent in bed with a naughty book and my vibrator. My subconscious wants skin on skin, heat on heat, and Will back in my bed, however that needs to happen. If he wants to tie me up and torture me until I beg him to end my erotic suffering—so be it.

I shiver despite the warm water and the heat building in my muscles as we push hard for the last five minutes of class. I’m not only willing to endure such a thing, I’m intrigued by the possibility of being at Will’s mercy.

More than intrigued.

I want that, I realized last night once Will left and the panic began to fade. I want more than knowledge. I want experience. I want to dive into this headfirst.

Yes, I might end up bruised and battered, but diving in is the only way I’m going to know if Will and I can really make this work.

I want to talk to Sabrina about my realization, to see what she thinks about lessons that involve less talk and more action, but my sister is clearly not going to be a font of wisdom on this particular subject. Bree is a clever, focused, compassionate human being, but she’s also a virgin who’s never been in a serious relationship. There’s only so much advice she’s capable of giving, and I’m way too shy to talk about this kind of thing with anyone else.

Bree and I aren’t just sisters—we’re best friends and have been since she was old enough to hold on to the waistband of my jeans so she could toddle behind me as I trekked to the sandbox our dad had built us in the backyard. No one in the world knows me like Bree.

Besides, most of my other friends are married to Will’s teammates. And though I could ask them to keep things confidential, I know how intimate relationships work. Sooner or later Diana or Amanda would let something slip to their husbands, and Will would end up getting ribbed at work for being a kinky bastard. And though I know he could handle the teasing—he’s survived almost a decade in the prank-infested locker rooms of the NHL and has the thick skin to prove it—I don’t want to be the one to leak his carefully kept secret.

After all, it might become our carefully kept secret some day, if I can muster up the courage to dive in and see if the water suits me.

So I keep my mouth shut for the rest of class, pumping hard for the finish line with the other mermaids, even as I vow never to come back to underwater spin class. Some combinations are meant to be—chocolate and peanut butter, kites and surfboards, movies and popcorn—and some are best enjoyed separately.

“Sorry,” Bree says as we turn down the resistance for the cool down. “The giggle fit is under control. I’m going to be mature now. Tell me all about your evening spent locked in a bathroom. How did you and Will leave things?”

I shake my head. “It’s fine. Forget about it.”

“No, really, I’m good now. I won’t act like I’m twelve, I promise.”

I wave a dismissive hand. “Seriously, it’s cool. I’ve thought things through and formed a plan of action.”

Bree’s lips turn down as she pouts. “Now I’m sad. I’ve let you down. I’m sorry.”

“You haven’t let me down,” I say with a laugh. “Now tell me about your night. Did you end up going out with the guy who was raised in the commune?”

“I did. Unfortunately.” Bree’s green eyes roll toward the ceiling. “I swear to God, the next guy who says he’s thirty and shows up wearing Birkenstocks from when he used to follow Phish and spray-on hair to cover his bald spot is going to get a swift kick in the shins. If I wanted to date someone old enough to be my dad, I would have set my preferences to include ‘older than dirt.’”

I grin. “Aw, come on. You know you have a thing for canned toupee hair. It’s like silly string, but for grown-ups.”

“It is nothing like silly string,” Bree says, decidedly unamused. “Silly string is fun. Wig whiz is an abomination. And you have no idea how hard it is out there in the dating-app jungle. I did end up connecting with this other guy after I dumped the Crypt-Keeper, and he was pretty interesting, but that is definitely the exception, not the rule… Be glad you skipped this part of the modern mate-finding process.”

“You could always do it the old-fashioned way,” I say with a shrug. “Go meet someone at a bar or a club or something. Or try speed dating!”

Bree shudders, her eyes closing as she shakes her head. “Please, sister dear, don’t act old. It’s so sad when you act old.”

“I’m not old!” I flick my fingers, splashing water on her midriff. “Speed dating is still a thing, right?”

“Sure, it’s still a thing,” she says, flicking water back in my direction. “And my friends and I are still churning milk to make butter in our spare time.”

“Brat.” I splash her with more force this time, making her gasp as water lands on her shoulder.

“Stop it. If you get my face wet and my mascara runs, I will have to kill you.”

I widen my eyes and fake a terrified gasp. “Oh, no, I’m so scared. Please, scrawny former model girl, please don’t hurt me with your non-existent muscles.”

“That’s it,” Bree says, hopping off her bike. “You’re going down.”

“No, wait, I was just—” My words end in a gurgle as Bree tackles me, knocking me off my bike and into the water on the other side. My head goes under and my nose fills and by the time I break the surface—sputtering and coughing—I’m hell-bent on revenge.

“Ladies, please!” Kyle shouts as Bree takes off up the row of stationary bikes and I follow, hot on her trail. “Back on your bikes! Only quitters skip the cooldown.”

“I’m sorry, Kyle,” Bree huffs as she fights her way through the water in a slow-motion sprint. “My sister’s lost it. She’s snapped. I don’t know what’s gotten into her.”

“You knocked me off my bike, you scrawny liar,” I say, inspiring a wave of laughter from the rest of the class.

“It’s true,” a voice pipes up from the back row. “I saw it go down. The tall, skinny one started it.”

“Lies!” Bree gasps in outrage, but her lips are curved at the edges. “I would never.”

“Get the skinny one!” another voice calls out. “Don’t let her get out of the pool without going under.”

Within moments, the class has devolved into a splash war with Bree and a few of the super fit and fashionable girls from the front row on one side and us mortals of average height and fashion sense on the other. But it’s a playful, giggle-fueled war, and by the time we all straggle out of the pool, we’re all smiles.

“That was fun,” Bree says, slinging an arm around my shoulders. “I like being ridiculous with you. Don’t ever completely grow up, okay?”

“Never,” I promise, meaning it with my entire heart.

I’m never going to grow out of being silly with my sister or taking part in an impromptu splash war. But it’s time for me to grow beyond the anxiety that’s had me tied in knots since I learned that Will is my Discreet Gentleman.

It’s time to woman up and face the challenge the universe has placed in my path. No more running or hiding.

Now I just have to figure out how to tell Will I’m ready for the “hands on” version of Lesson One…