DH has been good friend with E for many years now, even before we started dating, and both of them normally meet with another friend, B, to watch the footie or catch up over beers and food...
A few years ago, DH and I started hanging out more with E (who was then single) and B and his girlfriend. The 5 of us became really close, and usually did things together, dinners at each others places, nights out etc.
E met this girl last year and they quickly got a baby which made their relationship quite serious. Of course she became part of our group of friends and it was all 3 couples meeting up etc.
E's girlfriend is having a big birthday party in a few weeks and she invited DH and I. I found out yesterday that B and his girlfriend had not been invited.
AIBU for thinking this is an awkward move and potentially quite rude to B and his GF?