I know I'm probably being unreasonable but our family and DSIL with her DH and DCs had agreed to go on holidays together this year. One of the main reasons is that our dds are both aged 13 and will be good company for each other as they're at an age where they're too old to enjoy doing the things the smaller children enjoy, but far too young to enjoy adult stuff. We're renting two houses and dd is staying in SIL's house and SIL's son is staying with us and our DS who is a similar age.
However SIL rang me this morning to say that her dd is now bringing her two best friends from school with her. I know she's perfectly entitled to if her parents are agreeable to it, but you know how cliqueish girls of that age can be, and I'm afraid dd will be pushed out a bit and feel like the interloper, even though it's her family holiday too. DD looked a bit crest fallen when I told her and I've been doing all the 'oh you'll have much more fun in a group' 'I bet you'll be delighted they came when you get to know them' stuff.
BUT AIBU to feel a bit put out and wish they hadn't bee invited? I know I probably am being, really, but not sure.