My name is Brooke. I thought I knew everything about my boyfriend. Turns out, I don't even know which one of us he's actually dating.

Marcus and I met on a dating app eight months ago. He was charming, attentive, almost too perfect. The kind of guy who remembers your coffee order and texts good morning every day.

I fell fast. Maybe too fast.

We moved in together after six months. Everyone said it was too soon. I didn't care. When you know, you know. Right?

Last Tuesday, I knew something else entirely.

Marcus was in the shower. His phone buzzed on the nightstand. I glanced over — not snooping, just instinct.

The screen lit up with a notification. A text from someone named "B" with a heart emoji.

"Last night was incredible. Can't wait to see you again, baby."