I [53F] just lost respect for my son [28M]

My son is, on the whole, a person I’d call a good man. I was a single mom and it wasn’t easy because he ended up having a lot in common with his father, but he’s a responsible, self sufficient adult. He has a career he loves and lots of friends and 24 hours ago, I’d have counted myself as one parent that could say she was one of the proudest mothers out there.I suppose that everyone is human and flawed, though.Today I texted and asked him to remember to pick up my pain medicine from Walgreens (I just had knee surgery and he’s been spending nights at my house to help take care of me). He called me back and said he had asked me to send the prescription to a different store than we normally use. He did ask me to do that, but I forgot.He was strangely upset and very much did not want to go to that Walgreens. It was early enough that I could have called my doctor and asked if they could send the script to another pharmacy but then I decided to ask just why this was so important to him.He eventually confessed to me something that truly disgusted me. He’s cheating on his girlfriend with one of the girls who works in the pharmacy. They both think he’s only involved with them and them alone. He knew the girl he’s cheating with would be at work and he had his girlfriend with him today.I couldn’t believe it. He told me like I was his frat brother. I told him that I was extremely disappointed in him and that I’d lost a lot of respect for him. I told him I thought he had more honor and integrity than that.I know both of these young ladies and they’re both very sweet girls. It hurt my heart to know my son is treating people this way.I called him a few hours ago and told him that either he would confess or I’d tell them myself because he’s risking their health as well as being a fucking asshole and I know I shouldn’t have said that but I was fuming in the moment. It’s not an excuse since I shouldn’t speak to anyone like that.I still love my son, of course, but it’s just jarring. It’s like realizing your parents are human, only somehow harder because you wonder if something you did or said or showed them made them think this was acceptable behavior.I’m hurt by this and really I’m struggling with my emotions. Have any of you got experience with something like this happening? via /r/Parenting https://ift.tt/2MPmkc8