What is wrong with my cat?

Hmm I don't think anything is wrong with your cat he might just want to mark he's territory. Or maybe he just likes the smell?? As odd and gross as that sounds! hahaa & I know what you mean about having a twin bed and it being EXTREMELY small, my cat does the same thing every summer she loves to wake up in the middle of the night and starts jumping around! It's really annoying! But I'm sure your cat is just going through a weird phase and will get over it soon. (: