So Here's What Went Down

Met Alex through a work conference. Long-term girlfriend of two years at the time. Kept telling myself we were just friends, but we'd flirt in ways that crossed boundaries. One night, she came to my dorm for help with an assignment and it was so obvious neither of us wanted anything platonic. We ended up having sex... It wasn't just a slip-up, it felt like I was living someone else's life. I know my girlfriend trusts me, but here we are...