Is it ever ok to call a child stupid/idiot even in a joking manner?

I’m seeing a girl who has a 3 year old son, I’ve been on the phone today with her and her son was acting up, he broke one of his toys and while dealing with him she said something like “what did you do that for” followed by “ya idiot!”. Later something else happened and it was the same thing followed by “stupid!”.Writing this out makes it sound worse than it is, both were said jokingly and she never got angry or raised her voice and the kid was laughing, but I didn’t really agree with it it just make me think I’d be pretty mad if we had a kid together and she said that to my child. I’m just wondering if this is acceptable behaviour or am I just overreacting? via /r/Parenting https://ift.tt/2t3cHCc