Got an Answer?
Maybe there are some lateral solutions to this, that gives everyone a break from the stepdaughter (not making judgements about her, but I know how complex the step relationship can be and sometimes its nice to step away from that for a little time). Maybe dad could come over for dinner with you and the children a couple of nights a week (assuming you two have a good enough relationship and you're okay with it). Or the kids could suggest a dad date outside the house. Maybe they could visit him for an hour or so after school every day rather than for a weekend at a time.
How old is the stepdaughter? I'm a stepchild myself and remember being very conscious of being an "old egg" in a new "nest". Not in a bad way, but I did clue in to the fact that sometimes my stepdad just wanted to spend time with his kids (my half siblings) and my mum. Not always. And he certainly never made me feel unwelcome. But I recognised that they needed to make their core happy family memories and sometimes it wasn't with me in them (like visiting his mother or siblings etc, taking them to do little kid stuff that I was too old for). Same for my stepmother and her kids (not my half siblings). Sometimes they had some family thing on that just happened to be on the same day I was meant to be visiting. What better time to pick up that extra shift at maccas than when my stepsister needed my dad to focus on her.
But in saying that, I was a teenager for this stuff.
Maybe dad and stepmum could have a gentle talk with the stepdaughter about how dad needs special time just with his 2 big kids.
Can you show him this post?
I think I will invite him for dinner to talk it over. We usually get along, I shouldn't have got involved on the weekend but it's frustrated when my son called and asked to be picked up. It's not that I don't care about the girl, but my kids can't miss sport for no other reason than she didn't want them to go.
It is up to the mother to organise. If kids are allowed to work it out themselves it can backfire like you suggest.
They can end up seeing their father alot more than is good for them. Beware.
I guess that's open to perception because I know some pretty loopy fu****g women out there with children.
Personally I would ring a lawyer or legal service and ask. I think they are old enough but like you said you are worried that they won't have a relationship with him. They come above the step daughter so maybe suggest they go on a different weekend if she isn't there