Not quite Mexican House Thief - at least not yet! - but I'm trying no to get dragged into this and would welcome anyone's advice
Friend A has a holiday home in Florida and was persuaded to offer it to son of Friend B for a free fortnight's holiday with his girlfriend
Friend B's son (23) invited a load of mates to go instead, claiming his GF couldn't make it, but didn't tell A about this
Friend A - who's only just discovered this - has said no to the mates, some of whom are very dubious (a couple have convictions for affray)
Both B and her son insist flights to Orlando are all paid for, so it's now not fair to refuse them
As C I'm close to all of them, and though I'm trying to stay out of it I'm getting my ear thoroughly bent by everyone, expecting me to take sides. FWIW I believe B's son has been pretty deceitful over this and shouldn't expect to dictate who stays at someone else's home, but would be interested in the MN verdict
YABU = since flights are now paid for they should be allowed to go
YANBU = A should say no because she wasn't told those going had changed