DSD ruining my children's weekends

[HerGuy]

DSD has some issues with hunger, she seems to be fine 75% of the time, until she's anything but full (of food). Ie she goes from being full to angry,moody with no in-between of "oh I want food in a bit".

Last couple of weekends, she's ruled the weekend with her food issues and my two kids for the first time ever, made comment to their own mother about their miserable weekend.

Aibu to exclude her from activities with my own kids? My kids generally love her, and adore my girlfriend, but recently it's been ruining their time.

Do I tell boys that it's part of having a step sister, or do I remove her from the situation and let my boys enjoy their weekends with me.

For reference, we've been a "family" for about 18 months, but don't life together.

My girlfriend thinks me and the boys should do something ourselves, if her daughter is causing issues, however part of me feels that she'll never improve her behaviour if she's not included and held accountable, but then I wonder about my boys enjoyment.

Any opinions would be appreciated

Given that DSD mother is just a woman you are dating, I don't understand why you would inflict her behaviour on your DSs during your contact time?

Just do stuff with them and see your girlfriend separately.

My Dad tried to force his partner on us 3 DC and to this day we still hate it. I am now 52 and I really do not want to know about my dad's partner's DC. I know that sounds awful, but we have nothing in common with them and resent the relationship being forced on us.

When we were younger my Dad would make us go to parties they held, hang out with them, and later make my DC play with theirs. We went along with it to keep the peace, but I hated the fact that I couldn't just hang out with my dad on my own, ever, and resented both his partner and her DC. They didn't live together either. In the end I just hung out with him less.

That all may sound immature, but me and my siblings train of thought was that, she was his GF, and nothing to do with us, and we couldn't understand why he didn't see it and want to spend a bit of time with us one his own. She would openly also slag off my siblings to me, and compare us to her own DC.

My daughter is horrendous when she's not drunk enough water, and often mistakes being thirsty for being hungry?

My two pence - I don’t understand why people insist on forcing children together when everyone is happier apart. It’s like the principle of being in each other’s company is more important than enjoying each other’s company. My DH is guilty of this so I speak from experience. Have your time apart, everyone will have a better day.

Going out on a limb, she might be angry that her family has fallen apart and instead of having any quality time with her mum, she's having randoms forced on her?

It's really damaging to her development and her relationship with her mum to be forced into intimate family-like sitations with strangers. She doesn't have the language skills to say so, so it's coming out in random strops.

Can you and your girlfriend not just arrange babysitters and go on dates?!