How do you politely say don’t touch my belly?

Went to an event over the weekend that got me thinking... how do you stop random people or distant family friends from touching your belly?

I’m not trying to be rude and be all “bitch, hands off” but I only allow my mom, dad, husband, and sister to touch. My in-laws and I don’t get along at all. I have asked my family that I’m ok with to not touch the bump in public, only private settings, so the others have no idea they are missing out.

Hubby and I are just aware and sensitive to it all. My body, my rules kind of thing.

Any go to phrases that work?

Thanks!!!