PDA????

Is anyone else super uncomfortable with PDA. Like I'll hold his hand in public, and maybe a quick hug. But he is constantly trying to make out with me, or hold me from behind as we're waiting in the checkout line, or trying to cuddle with me in public, like at a restaurant. It's really just not something I'm comfortable with, and he gets so upset. I'm down for anything at home, but I'm not a teenager, I'm an adult and we have a child. Is there a way I can get him to understand?