Smacking kids? Over it

My fiancé smacks our daughters, I do at times when it’s really necessary but it’s a little tap & never hurts them. I know some parents smack their kids too but I feel as though my partner does it way to hard and way to often, he just smacked our daughter twice during one 2 min nappy change. Idk if it’s just me overeacting about how hard he hits, but I know it’s 100% way to often, to many times, especially over little things. Its starting to make me feel like I’d rather do this all without him, I don’t want my girls growing up like this, well with a father like that.

YAS I’ve tried to talk to him about this & he just brushes it off and ignores me like it’s nothing, thinks I’m just overreacting :/