I know they're not mine but

[Vivi86]

I don't get my parnter. How this started he has kids from a previous relationship. My sister is having an engagement party. She invited us him and his ex have their weeks. The party falls on his week so we have them I just told him you are stressing out why well because its going to be too late for the kids.  But their bedtime is 9:00 then on weekends its basically midnight. I told him Idk why you're stressing out the kids already go to bed too late.(Bedtime is 9:00) but the kids always have something to do to stall and they also say they aren't tired they end up going to bed at 10:00-11:00 pm. I would like them to be there. Parents I need advice. I'd also add that everytime we go or have a dinner while driving back the girls are always sleeping. To me it doesn't stress me also I think of them as mine. 

[basil67]

Get a babysitter, or leave the party a bit early.   

Much of parenting is compromise

[ShyViolet]

Why is it such a big deal to you for the kids to be there?  Let your partner decide.  At the end of the day they are his kids and it's not your place to insist on something like this.  If he doesn't think it's a good idea for them to go, really what is the big deal?

[Sanch62]

If the kids are invited, I'd first try to negotiate with my partner without being dismissive of his concerns. That's not negotiating, it's arguing. I'd offer him something of value to him in exchange for the favor to me. Sweeten the pot.

If partner still remains a 'no,' I'd ask whether he can try to switch weeks with his ex to attend, or whether the two of you can hire a babysitter.

If that's a no, I'd arrange for someone else in my family to be my 'date' and go enjoy myself to celebrate my sister.

I would not harm my relationship by criticizing my partner's parenting decisions. Those are his kids, and that's his department. I would respect that.

[MsJayne]

It's his week for the kids and it sounds like he's using them as an excuse for not going. Why can't you just go to the party alone?