My cat and my comforter! lol

My cat is acting strange to me, but perhaps it's not so strange at all. What he does is when he gets on my comforter, he will take some of my spread into his mouth, and rock back and forth. It looks like he's having sex with the comforter. ( I say looks b/c I've never seem him have sex. It's my sister's cat and I'm taking care of him while she's in college She says she's caught him doing it several times,lol ). His whole back half sways, and he's arching his back up and down, and etc. He's moving really fast and kneading his paws into the comforter. When he gets excited like this, I can see his sex organ too, and he is like in some kind of trance. I can try to push him away, but he is determined.... That's what made me think this might be sexually related. In any case, I'm getting him fixed soon. Will someone tell me what he's doing, and why?

You guessed it right. He's getting frisky with your comforter. Getting him neutered will help but my cat Ripley has been neutered for over 12 years now and he still does that sometimes. It's just natural.

Welcome to Pet Talk, hope you stick around and come over to the Cat General board and introduce yourself. We're all friendly here.