Sorry, this is quite trivial, but I need to unload.
DS's birthday is next weekend. Invited family (both sides) round for celebratory bbq as usual. DS is also having small party for 8 schoolfriends the following day. We haven't invited any of DS's cousins to the party, as they do not know his friends, and would presumably be at the bbq anyway.
BIL and SIL called to decline the invitation to the bbq as they don't want their DC eating greasy food. (That's fine. They never come anyway, and we always try to guess what the next excuse will be.)
DH mentioned the children's party (he regrets it now) and BIL is offended that his DC have not been invited. DH pointed out that none of DS's cousins from my family have been invited either, as it is just for schoolmates, and also that BIL's DC are quite a bit younger than DS, so might feel intimidated by a gaggle of older kids. BIL later sent DH a text to inform him that he and SIL are unhappy and disappointed that we do not realise how mature and advanced their DC are, and that our DS's birthday will be ruined for not seeing his cousins.
WIBU to text back and tell them to just F-off? They always make me feel so crappy and like I've made a wrong decision. I know that tomorrow I'm going to have MIL calling to 'mediate' (persuade me to invite the DC). Should I just give in and invite the DC anyway?