Wife cheated. (M,F)

So I’ll try to make this short and sweet. My wife cheated on me with my cousin. One night we were at a bar and got into a fight. I left her there. He gave her a ride home and fucked her on the way in his car. I still love her very much and don’t think she will ever do it again. I also have to admit after my initial anger wore off I found myself being turned on a bit to know that she took another dick. We’ve been together for a very long time and up until that night she has never even been naked in front of another man. Let me know your thoughts on how and what I should do?