Guilty Gym Secrets

I've been cheating on my girlfriend with one of my clients for months. It started small, just a few secret texts and awkward looks, but it spiraled into more when we finally gave in during lunch breaks at the gym. We're both adults who know what we’re doing is wrong, but there's something about the danger that turns us on. I feel so guilty every time she asks if I've been thinking of anyone else or calls me out for being distant. She’s never going to guess it was all for naught when she saw a different kind of sweat on my brow.