My FIL who already rolls his eyes at any kind of boundary I've tried to set for the wellbeing of my 10 mo DS (eg don't put his toys in your mouth during playtime, sharing saliva isn't the way to build his immune system!) encourages my DS to pull hard on his hair as a game. He'll lower his head and let my DS grab his short hair and then he'll shake his head around to encourage DS to pull harder and DS pulls really hard and FIL laughs. I'm concerned that with DS starting nursery in 2 months he'll learn that that behaviour is acceptable and start pulling the hair of other children. Am I being OTT? When do I stop my FIL playing this game? Would you make all visits supervised if you couldn't trust he would stop or play calmer games? FIL is a very old person with outdated views based on gender stereotypes and he's also an ex rugby player so he thinks he's doing the right thing with this game and never listens to anyone as he thinks he knows best.