Mother in law 😠😠😠

Was round my MIL's yesterday. My son is only 2 and a half months old and I'm not ready to leave him alone with anyone. She wanted me to leave him alone with her and kept prompting me to but I wasn't budging. My son was sitting nicely on my lap when she just came and took him off me. Not saying anything or asking. It really pissed me off. It's not like I haven't let her hold him or play with him. I found that really rude. Was very close to saying something but held my tongue. I don't go round people's houses and just take their kid from them. 😠😠😠😠 **UPDATED** I mentioned it to my OH and he said yeah well she is his grandmother. I said so it's rude to just take him. This was in front of my mum and she said yeah you can't just take him without asking first. Next time...I say something.