DS is almost 5 and has just started school, so has a whole new set of friends who he wants to invite to his party. However for the last 4 years his friends have been my friends kids. He goes to their parties and they come to his. This year we either have a massive party, which I can't afford, risk upsetting friends by not inviting their kids (even though we've already been to their parties or don't invite Ds's new school friends (obviously not an option as it's his birthday). How do you keep everyone happy?