Kissing babies

So the hot topic this Christmas was family kissing my six month old baby. We went to some families house last night and my husband‘s uncles wife who is not even blood related to anyone tried to kiss my son and I told everyone no one is allowed to kiss him! and it was the topic of the night. She was basically telling me that I’m crazy for not letting people kiss my child and she asked me if I thought they were nasty and ask if that was the reason why I wouldn’t let her kiss my child??! like RSV and the flu is just not a thing? like wtf. I was so weirded out.. I don’t let anybody kiss my child but me and my husband! I just find it weird that people feel the urge to kiss a child that is not theirs. I would never kiss someone’s baby other than my own I just find it so odd that people feel the need to kiss a child to show their affection.. what’s everyone else’s opinion on this because last night I literally felt like I was being attacked for not letting people kiss my baby. my in laws told me today, they don’t like the fact they can’t kiss him but they respect my choice. I just don’t understand the need or urge to kiss a child that isn’t yours!! Let me know if I’m crazy 😅