My 7 month old cat sucks my skin!!

My cat Pepper is 7 months old now.He sucks on any humans skin he can get to.Ever since he was 8 weeks old he started so now it's a habit and he won't stop.There's another problem.A couple weeks ago we got a kitten and he saw Pepper sucking so he started to suck on Pepper's fur.The worst part about it is Pepper is a boy.Our other new kitten sucks on peoples eyes.They just can't get enough...HELP!!