I have this really weird sex fantasy that I know I will never, and should never, live out as it involves i****t and cheating.

I want to have sex with my cousin's girlfriend in front of him while he's tied to a chair with his dick locked in a chastity cage while his sister grinds up against crotch. After I cum in his GF's mouth, pussy, and ass then I move on to his siter and do the same thing. Then after I finish with his sister I whisper in his ear "Have fun raising my kid and enjoy your new niece/nephew."

But I know I should never do this because I know it's wrong.