Others touching your bump

My MIL will randomly touch my bump without asking/warning e.g. in the lift or at her place. It will startle me a little because I am not exactly a physical touch person (like I don't hug my parents/PIL) but she seems to think that it's okay? Is it normal for me not to feel okay? Should I get my hub to talk to her? I mean if there's baby movement that can be felt from outside, I would think I will "invite" them to feel. but I'm only in second tri now and not feel much movement also. Like maybe if want to touch, is it too much of me to have her ask for permission first? I won't say no and will still cringe a little but at least I'm prepared?