My cat likes to lick my armpit!

He probably is just the reincarnation of a pervert.

he licks cause he can't believe what he smells and then rolls on the floor laughing making fun of your hygiene

He's trying to cllean you because you won't do it yourself, you dingus! Take a shower, jibronie!

My cat pushes the brush out of the way

My cat sniffs my breath and armpits especially when Im sick, I think they can tell a lot about your health through scent.

Sweat contains salt which is tasty to a cat. Pretty simple stuff, really.

My cat jumps in my lap whenever I brush my hair.

Cats are weird creatures. They do weird things. One of mine licks my feet, until I push it away.