Here's the thing: Without knowing the people involved, we can't say if the joke was being made ironically or not. If it was being made ironically, then those people would very likely not make such a joke outside of that very specific, private situation. In that case, it's not normalizing sexism at all but, instead, mocking/lampooning it.
The above picture is not sexism. It's not casual sexism, it's not overt sexism, and it's not normalizing sexism. Indeed, it's doing the opposite -- it's mocking sexism.
So. The question here is: Were your partner's friends mocking, were they making a stupid joke, or were they sincere? I think it's pretty likely that they weren't being sincere, but the only way I can say N T A is if they weren't making a mockery of the joke, and I can't necessarily trust OP, with her obvious agenda, to make that distinction.