Ex early 20s Father late 50s

We would always go hang out with her friends family because she was that close to them that they considered her like a daughter. However I noticed my ex would always avoid the friends father everytime we go over she did not even acknowledge him this did not sit well with me because it was disrespectful. I confronted my ex one day while we we're drinking at their place she balled up and told me that he had grope and tried to have sex her several times when she was over and drunk. This did not get me mad but got me hard! I later told her I will make it right and will make it all go away. Later that night the house was quiet me and the ex crash in the guess room next to the garage I got up and saw the father outside smoking so I decided to go chit chat and confronted him about it at first he got mad, scared and went into denial. However that all changed when I offer to let him smash her just once, he went quiet and then turn to me and said when? I told him I'll give him the signal to come into the room as I went back rock hard and positioned my ex in ass up face down doggie at the edge of the bed then open the door and waved at the father. He came over we turn on the light and his jaws just dropped I told him to hurry and I'll keep a look out. For the next 3 min all you can hear was him grunting and ass clapping, later he came out and headed straight into the house and didn't say a word as I went back inside and my ex stood up and said "that's it!? I wanted more" and blacked out again. She woke up thinking that we had sex that night. The father avoids my ex soon after and she couldn't figure out why but to ask me did I say something to him I just gave her the smirk and said no.