Everything with me and my girlfriend were going good. But in the back of mind I wanted sex with my ex. I didn't love my ex anymore, actually for a long time while I was with her. I think we both just shared lust for each other toward the end of our relationship. So must of the time that I was with my ex, all I wanted was sex. So one night I wanted sex with her. She came over in the middle of the night. We did it. It didn't feel like it used to. It felt empty and hollow. After she left, I took a shower. To wash off that whole time. The next day i saw my girlfriend, I acted as tho nothing happened. I regret that night. I regret hurting my girlfriend.