I'm organising a party right, because its my birthday and my best m8 is coming back from a year teaching abroad. All my m8s can make this one evening right, but my housem8 (who is also m8s with my m8s) is insisting that I have it almost 3 weeks after as she'll be away.

M8s, what do I do? Shall I say you're being unreasonable and have it anyway, or rearrange the whole thing to maintain housem8 harmony?