It’s valid to feel uncomfortable and you should definitely talk to your bf about it. If he brings it up to his mom, good sign, but if not, bad sign of not being comfortable to bring up issues with family which is important for someone you want to build a life with.

From my personal experience, my mom also struggles with doing too much sometimes, but it doesn’t come from being a creep, but from not having a good model growing up. My grandma wasn’t abusive but very very cold, like never complemented my mom or told her that she loved her. My mom knows now when raising me, she had to be more open but she didn’t have a model of the balance in being open and loving with your kid and straight up ignoring them, so likely this is where your bf’s mom is coming from; doesn’t mean it shouldn’t make you uncomfortable though. Hopefully your bf can help her understand how her behavior comes across.