Invite DD's friend to DS's party

[onthebus]

DS is 6 in May and we have booked his party at one of those soft play type places. When I booked the party, DS wanted 11 children to come. He has subsequently decided that "girls are silly" and no longer wants to invite the girls, leaving him with an invite list of 8 boys (all in Year 1). There are no other boys he wants to invite. Adding DS and DD (aged 4) into the mix we have 10 children in total.

However ... the soft play place insists on a minimum of 8 children. Based on others' experiences of Year 1 parties I think it is quite likely that 3 children won't be able to come and if this happens I'll be paying for more children than are coming which I kind of resent doing.

Also, now DS is not having any girls I realise DD is going to be stuck a bit on her own.

so I have come up with (but have yet to sell to DS) the "brilliant" idea of inviting the younger sister of one of DS's friends - who by happy coincidence is one of DD's closest pals. Thereby solving my "what to do with DD" and my "numbers" problems in one fell swoop.

Is this a really awful thing to do? (esp as DS thinks girls are silly?)
Could I hedge my bets and "not" invite her but ask her as a last minute standin if a few of DS's friends can't come? Or is this likely to "really"annoy the other mother (who I really don't want to annoy seeing as her children both like my children).

I'd sell it to DS as 'your sister has to be there,she 'might' annoy you and your pals,but if we invite x's sister she will have someone to play with and leave you and your pals alone'

i always invited one of ds's friends to dd's parties, (she has sn so he would be bored rigid otherwise) as long as you do it both ways, can't see the problem

My DDs were always allowed to invite one friend to their sister's party, mainly cos they are so different that neither liked each other's friends very much and the difference between 6 and 4 year olds is huge.

Not an issue now 10 years on!

So no yanbu

I like titch's suggestion. I think it is a fair thing to allow a sister to have just one friend for company at her brothers' party.

I'd sell it as "I pay for your party and its tough luck if you don't like it", but I'm a very very mean mama.

And point out to him, while you're at it, that it might work out well for him next time his sister has an all-girls party and he wants a bit of male support.

Definitely YANBU. I was always allowed a friend when sis had a party and vice versa. the friend is not being invited to your DS's party... they are being invited as company for your DD (IYSWIM).

Just present it as "DD's going to invite [little girl x], so she has someone to play with at your party".

No, you cannot ask a child to be a last minute stand in. She's a friend, not an employee, how would YOU feel to be a last minute stand in in case your mate's 'real' friends let her down?

You don't have to 'sell' the idea of inviting your daughter's friend - you tell him that this is what is happening. He's six, for God's sake, be the grown up.