SO jokes about baby

Toni
Sometimes my SO calls our baby girl a "spoiled brat" or a "cry baby". He says it in a joking manner but it still bugs me. She's just a baby so there's no way she's spoiled and of course she cries! She's only 4 months and that's what babies do. I guess it bothers me because I don't want him to say these things to her as she gets older and starts to understand. I have tried telling him not to say it after he does but he continues to anyway. He mostly calls her spoiled whenever she needs to eat bc "she's always on [my] boobs" or a cry baby as soon as she starts to get fussy.. Do you guys think I'm being too sensitive? Is it okay for him to joke this way? I just don't want him to get used to it. And if you don't think it's okay then how do I get him to understand that??