Don’t kiss my baby

Hi everyone! I have had a few instances where I’ve seen my MIL & her boyfriend kissing my baby on the face. I am 5 weeks PP. I told my husband he needs to speak up but he said he hasn’t seen them kiss the baby, he did tell them to give the baby back to me when he was crying but they didn’t listen. We are going to their house in a few weeks for a family event, how would you address this?

I feel like I need something to say before Introduce the baby to everyone else something along the lines of “You are welcome to hold baby but please don’t kiss him. And be sure to give him back to his parents when he is crying”should my husband be the one to make that announcement? I feel embarrassed to even have to say this given that they already don’t like me. Should we just skip the event? 😂 I feel bad because I know they got the baby gifts, I just feel like a child around them and the words don’t come out. I can’t stick up for myself/ my baby it seems like.