Am I being paranoid? Rant!

My LB is 9.5 months old now. For the past month, in order to fall asleep or soothe himself, he licks his hands. It works great for him. He also tries licking people, which is obviously a no-no, although we let him do it to us (mom & dad) sometimes. We are currently visiting my MIL. Generally she's a lovely lady, really nice and caring, but when it comes to LB, she's just super annoying, disregarding rules etc. To be clear, I do not have many rules. It's stuff like: 1. Please don't disrupt him while he eats (he will get fussy and stop eating) 2. If he's playing happily, please don't stop him to take him in your arms (he's great with independent play and that works for us) 3. Please do not disrupt his routine so you can have fun (wake him from naps, push back feedings etc) My most important rules regarding LB are "no kissing LB's face and hands" and "don't let him lick you". My MIL keeps taking the piss with those! We don't speak the same language so telling her off is not easy. My husband constantly tells her to stop but she just plays dumb! It annoys me so much, I'm just chasing after LB to be cleaning his hands! I know he crawls around and his hands get dirty, I just find people's mouths way worse! She's also part of the generation that feels the need to lick their lips before giving a kiss which is just disgusting! My parents know the rules and they always adhere to them. They even go as far as asking before doing certain things just to make sure. They understand how easy it is to get the baby sick by not knowing you are sick yourself/not having symptoms. Also, LB spent time in the NICU as he was born prematurely and had issues with his lungs and breathing, so yeah, I am extra careful. Am I crazy for wanting MIL to freaking stop kissing the boy's hands???