Sigh I don’t know what to say?!

Dude i dont know what to do!..the guy I’m dating and I will be having a great time and then suddenly he’ll just start talking about my stomach or like I’ll sneak up behind him and he’ll reach around and Pat my stomach and be like “I feel your stomach”— I’ll tap his face and say “stop being so rude” or I’ll just plainly say “stop it” but he keeps doing it and I don’t understand why he can’t let it go. It makes me feel bad and it truly does ruin a good time 😕 but like he just won’t stop I don’t get it!… I know I don’t have abs anymore but I’m working on it. It’s not like it happens in a day! It’s not like I’m over weight! I’m just not “tight” as I used to be.