I didn't know my girlfriend's ex boyfriend was in town for the long weekend. I came home early from work to catch them fucking on my sofa. I'd come in from the garage so they didn't hear me come in. Soon as I saw what was happening I hid behind the wall and hit record. I got so hard listening to them. I had to stop recording about 3 minutes in because they changed positions and I was afraid of being seen. I left and text her an hour later saying I was on my way home. When I got home she kissed me deeply and acted completely normal.