Sister in Law

My sister in law Kate and her husband decided to meet us in Jamaica. One afternoon I left my wife at the pool and headed back to the room for a nap. I lay down and started to hear noises in the next room. I assumed Kate and her husband were having a little fun but there seemed to be more voices. I put my ear to the wall and all I could hear was Kate's husband instructing someone to fuck her harder. I went out on the joint balcony and peaked in the room. Kate was fucking 3 black men as hard a she could and her husband was enjoying the show jerking his cock. What did I have to lose so I slid the door open. Kate never looked up but her husband saw me and didn't know what to do. I put my finger to my lips and pulled out my cock and pointed it at Kate. I know he didn't want me to but I went over to the bed and planted my cock in her ass. I fucked her ass until I shot in her. I don't think my wife or Kate know but he knows I fucked his wife . I think he kind of liked it.