I don’t know is anyone posting on this thread has actually ever had to share their DC with their ex and new partner, but OP’s worries are normal. Her child is 5. She still very little and OP wants to protect her. It’s really unsettling when your child is going to stay over at someone’s house you barely know
Plenty of us have been in the exact same situation as both the OP and her ex’s partner. We can see it from both sides, in both the situation this thread refers to, and the previous thread where OP posted about her texting the ex and being asked to keep it business only.
Blended families are hard. Everyone has their own ideas about how it should work. But no step-family has ever thrived without some understanding and boundaries put in place by all parties.
I say this as someone who is considering going on a holiday with my ex and my DP, and who regularly spends time with my DP’s ex/in-laws etc.
It’s hard when others don’t see the issue but your gut is screaming “I’m not comfortable with this!!!” when sometimes you can’t even articulate why. It’s not always the obvious thing that is upsetting, but what it represents.
People (myself included) have been harsh on this thread because they fee frustrated that even when it’s pointed out that this behaviour is not ok to ex and his DP, the OP seems determined to say “but it’s ok TO ME, I can’t see a problem and therefore it’s ok”.
The most important person in all of this is the DD (and indeed the DP’s 2 kids too) who need to feel that they are equally important to the adults in that house. That’s on dad and DP to ensure.
OP can be there to support her DD and to assist IF AND WHEN needed, but by preempting problems that haven’t even happened yet she’s just borrowing trouble from the future.
OP take a step back. Let DD enjoy her time with her dad, don’t ask the details about how they decorated the tree or pry for any info you can use to prove a case against your ex and his DP.
Try to be upbeat and relaxed about it and then your DD won’t pick up on your stress and anxiety over this. If there are any issues they will come to light naturally, you won’t need to force them out of her. If you make a big deal about it she’ll notice your negativity and feel uncomfortable talking to you about her time with her dad.