Can't stop thinking about my wife's affair.

My wife had an affair 3 years ago, I forgave her but I can't stop thinking about the affair and knowing details.  So in 2015 my fiance at the time confessed to an affair with a co worker.  She works at a hospital as a supervisor and she had this one employee of hers who she became very friendly and attached too.  He was a young single guy who would always hang out with us and friends and would never bring anyone.  I started noticing how my wife acted when he was around always very happy and laughing alot she would always call him to come out with her and her girls.  I started feeling threatned by him so i told my wife I only wanted her around him if I was there.  She would always say I was overeacting and they were like brother and sister.  Well let me say me and my wife werent having the strongest relationship at the time we would argue alot and go days without speaking.  Also just to add we have 2 kids together.  Well anyway in Jan 2015 I noticed she was always acting strange around me and I ask her one night did she have something to tell me.

Well she said she had let someone get too close to her and it was her employee who I always feared.  She said it was a 4 month affair where they were sneakinly texting each other late when i wasn't around and they would hang out together but she would tell me she was with her girlfriends. and so on.  Then she said one night she went out with 2 of her girlfriends to a bar got really drunk and afterward called him and said she wanted to come over.  Now here is the part thats driving me crazy.  When she first confessed she told me they kind of had sex. I asked what does she mean and she said it was very intense and physical and alot of rubbing. Then later on she said to her they did have sex because he private part was touching and rubbing around it.  Well I respect that she confessed but she made up a phony storie about what happened.  she lied, she said they were hanging out together and after he invited her to his car and they started kissing in the car.   Then the next day she sat me down and said that wasn't true what happened was she left the bar and called him and went to his house.  She said she felt so guilty and had to tell me and that she was really drunk and only went to his house to sober up before coming home.

Well I forgave her and we got married but I can't stop thinking about what really happened with them.  She refuses to talk about it now and just wants to move on. What should i do?  its been 3 years I need help, i cant get the thoughts out my mind.  I want to ask more questions but she will just get mad.  She still works with this guy but says its cut off and they only talk about work.  From her answers i'm not sure if they actually had sex or was just rubbing on each other.  Can someone give me some advice?