Had some family over for New Year’s. My son invited some of his co workers over. He said that he would be right back because he was going to show one of his co workers (female) where the bathroom was because she needed to use it. I noticed that he was not back after 10 minutes so I had walked into the house and I checked the bathroom and there was nobody in there. I started to cough for him from the bathroom door, which is at the very front of the house near the garage, but he didn’t answer. I walked to his room, which is at the very back of the house and as I got close, I noticed that his store was halfway open and he usually closes it when people come over. I seen his underwear thrown on the floor near his door and didn’t put too much thought into it and I open the door and saw him having sex. He noticed that I had walked in on them and I just walked right out without making it obvious cause I didn’t want her to feel embarrassed. We ended up talking about what happened this morning. Not sure if I should have mentioned it or if I should just left it alone?