I'm throwing a big party in a couple weeks, most of the attendees will be my age so invited my parents best friends ( through them) so they would feel less out of place .
Parents said that their friends are at an event with their son that day, so could they bring him along. I said no problem but asked them to double check that timings don't clash with my event which is unusually in the afternoon they said they would.
Rsvp date is long past and I sent a note out to everyone who RSVP d thanking them and letting them know local places to stay for etc.
Parents friends have come back and said they can't make it as the times clash and they let my parents know this.
I've already paid for them at nearly £30 a head. I'm less annoyed about the money than I am about the lack of consideration from my parents! When I asked them what's going on they just said oh yeah it's a shame they can't make it, they had the other event booked first 
Obviously parents friends are not at fault here, I'm just irritated at my parents!
Aibu for being annoyed about this?!