He keeps touching me when I don't want him to

My boyfriend would never intentionally make me feel uncomfortable or upset, he just doesn't understand that he can't touch me whenever he wants to if I've said I don't want him to.

It's isn't anything big like him trying to finger me etc when I don't want it. It's jut like touching my boobs or legs or my body in general. He'll squeeze my boobs in a joking/playful way when I've told him 5 times 'hey, I'm not in the mood to be touched right now' and I guess it's his way of being funny or whatever.

Then I get really irritated and snap at him, then he thinks I'm being 'pathetic' for getting in a mood. It's so damn annoying and I wish he would stop it.