Brother-in-law Cums in Wife's Hot Sister to get back at Cheating Slut

I went into my brother-in-law's room to see if my sister was home. I wanted to see if she wanted to go out and have some fun. He was already under the impression I was going out with her tonight. We had no plans. He was so upset that his suspicions of her cheating were correct. He said he wanted to get back at her, so I fucked him until he came inside of me. Sweet revenge!