What do I do?

[MoiraRosesMeltdown]

This is the type of situation I struggle with as a parent.

The girls in DD2's class have been invited out bowling by her friend's mum. Three of them are going. DD1 (8) was very excited.
I got a text today inviting DD1(10) too since someone else's sibling is going. DD1 is desperate to go.
But, DD2 doesn't want DD1 to go and is now refusing. I said to go ahead and refuse, and that her sister would go alone. DD2 is now crying because she wants me to tell her sister not to go.
The way I see it is that DD1 has done nothing wrong so I don't feel I can disappoint her. DD2 shouldn't get her way own way for being difficult, but she was so excited before that I don't want her feeling disappointed either.
I'm working so can't go. I don't want to risk DD2 (can be very moody and difficult) being grumpy for the other mother.

I have dd 10 and dd 11. They have their own friends though do jointly mingle at times. . If they decide the dsis isn't welcome then that's fine. . Even if the dsis is disappointed. .

Maybe try getting her to look at it from her big sister's point of view - how would she feel if she had been invited to something and was very excited about it but couldn't go because her sister didn't want her there.

If all else fails take older dd out for a special treat while younger dd is bowling

So I should try to persuade DD2 to be happy her sister is going. failing that, allow DD2 to go alone? I would feel so sorry for poor DD1 who is being denied a bowling trip for doing nothing wrong.
This is why I struggle. I can always see both sides. Voting is a nightmare!

I would tell DD2 that DD1 has been invited by her friend's parent therefore it's not her decision, it's not your decision, it is DD1's decision as to whether she wants to accept. That's how invitations work and the same courtesy will be applied to DD2 whenever she is invited somewhere (presuming no bad behaviour, age appropriate etc etc). Also try to get DD2 to put herself in DD1's shoes - she should be able to do this by age 8. Disclaimer: I only have a baby boy so what do I know

I agree with red. You didn't ask if DD1 could go, she was invited.

Depends - does DD2 go with DD1 friends?

Don't let DD1 miss out by giving in to DD2! It's not fair to cancel the older one's day out too to give the one who's behaving poorly their own way.

That really is a tricky one. If you know the birthday girls mum well I'd be tempted to send them both still but be prepared to have someone collect either should they misbehave at all.

Or take neither of them and treat the one that missed out unfairly with something else. I can understand a child not wanting their friendships encroached upon by their sibling but they do have to learn that they do not have ultimate control over these things.

They are both going with strict instructions not to fight!