My SO doesn't understand..HELP!

The sore boobs and sensitive everywhere else. He always grabs my (noticable larger) boobs or smacks my butt. I've tried talking calmly to him about it, I've blew up about it, I've tried hitting him back (playfully of course). He won't let up. When I tell him it hurts his reply is "don't be such a bitch" and then HE proceeds to get moody, or "you're just being a baby". I'm honestly sick of it and don't know what to do..HELP!