My DP has always had a relationship with his sister where they call each other names, possibly more from his side than hers. The stuff that's made me uncomfortable in the past has been him teasing her over getting too old to conceive etc in front of their parents, who just lightly go, 'oh don't be so mean'. Anyway, now she's pregnant, it's stepped up a notch, to include constant remarks about how fat she looks, letting herself go etc. I've told DP how awful this is. His response is, 'but it's true. she doesn't mind'. And she responds in a lighthearted way. She's also married someone who she is exactly the same with ie. they call each other the c word, berate each other about their weight etc. AND on top of this, their work environment is the same - they work together - and other men at work have told her how fat she is etc (don't think it comes from the women, from what I can tell). DP and SIL say this is banter.
I think a) they wouldn't say it to their mum and b) if anyone spoke to dd like that I think and hope DP would be furious.
My worry is that DD will see how DP is with his sister and how she is with her husband and get a warped idea of how men can talk to and about women. That what I consider bullying, disrespectful and mean is just 'banter'. I really think banter is just bullying under a different name designed to make the victim seem like they have 'no sense of humour' if they get upset. I think they're being immature twats quite honestly.
I can't make DP see sense, although I haven't suggested a) and b) to him yet.
What do you think? Is this kind of interaction okay if both parties seem okay with it? What do I tell DD?
NC for this one.