A neighbour throws a party and invites a,b,c,d and e.

a,b,c,and e have had a long standing gripe going with d.

They spend all evening bitching at him and about him.

The neighbour has chosen for d to be invited to the party and has no intention of asking him to leave to suit a,b,c and e.

Everyone else at this party has to listen and watch a,b,c and e whinge all night. None of them have a problem with d either.

Who is ruining the party?