Chapter 1

"We should start working out together," I said, sliding into the seat across from Beau at our favorite breakfast spot. "For the wedding."

Beau looked up from his phone, his dark hair falling over one eye in that way I'd always found irresistible. "Working out?"

"Yes! I know neither of us are gym people, but wouldn't it be nice to both look our absolute best for the photos?" I reached into my purse and pulled out two glossy membership cards to Elite Fitness, the upscale gym near our apartment. "Surprise!"

I'd spent weeks researching the best gyms in our area, finally settling on Elite for its clean facilities and variety of classes. The memberships weren't cheap, but our wedding was only six months away, and I wanted everything to be perfect.

Beau's smile flickered for a moment as he took the card. Something flashed across his face—hesitation? Concern? But it disappeared so quickly I thought I'd imagined it.

"That's... thoughtful, Liv. But you know how crazy work has been. I'm not sure when I'd find the time."

"We'll make time," I said, reaching across the table to squeeze his hand. "Even just twice a week. We can go together after work. It'll be fun!"

He nodded slowly, sliding the membership card into his wallet. "I'll try."

---

Three days later, we pushed through the gleaming glass doors of Elite Fitness together. The air smelled of disinfectant and faint sweat, masked by some kind of citrus air freshener. I felt a flutter of excitement—this was something new we could experience together.

"First time?" asked the perky receptionist as I fumbled with my new membership card.

"Yes, we're—"

"Hey, Beau!" The receptionist's face lit up with recognition. "Haven't seen you in a few days."

I glanced at Beau, confusion washing over me. He shifted his weight from one foot to the other.

"Yeah, been busy with work," he said quickly. "This is Olivia, my fiancée."

"Nice to meet you!" she chirped, but I barely heard her.

As we walked through the gym, I noticed several staff members nodding at Beau. A tall trainer with a clipboard called out, "Missed you yesterday, man!"

"You've been here before?" I asked, trying to keep my voice casual as we set our bags down in the free weights section.

Beau shrugged, not quite meeting my eyes. "Just a couple times. Wanted to check it out before we committed, you know?"

"A couple times? They all seem to know you pretty well."

"I came by to look at the facilities. Asked some questions." He picked up a dumbbell, effectively ending the conversation.

Throughout our workout, I couldn't shake the feeling that something was off. Beau moved through the gym with the confidence of someone who knew exactly where everything was. He adjusted the machines with practiced ease, never once looking at the instructional diagrams most newcomers relied on.

When we finished, I was sweaty and slightly out of breath. Beau barely looked winded.

"I'm going to hit the shower," he said, kissing my cheek. "Meet you in the lobby in fifteen?"

I nodded, watching him walk away. His phone sat on the bench next to me, abandoned in his haste to escape my questions. I stared at it for a long moment, an uncomfortable feeling settling in my stomach.

I'd never been the type to snoop. In our five years together, I'd never once felt the need to look through Beau's phone. Trust was the foundation of our relationship—or so I'd thought.

But something wasn't adding up.

I picked up his phone, intending to take a quick selfie for us to commemorate our first gym session together. The screen lit up at my touch, and I noticed his fitness app was still open.

That's when I saw it.

A notification banner across the top of the screen: "Congratulations! You and C.M. have unlocked the Couples Running Challenge badge!"

I tapped on it, my fingers suddenly clumsy. The badge showed two silhouettes running side by side, dated just two weeks ago. Below it was a list of shared workouts stretching back months—runs, strength training sessions, even yoga classes.

All with someone whose initials were C.M.

Definitely not me.

The phone nearly slipped from my suddenly numb fingers as ice spread through my veins. I'd never done any of these workouts with Beau. I'd never even been to this gym before today.

Who the hell was C.M.?