To tell DP not to stay at his ex's?

[george0pig]

I'll keep it brief. I've never had a relationship with someone with DC's from a previous relationship so I'm not sure if I'd be completely out of order even having anything to say about this, so please help!

DP's DC have asked him to stay at theirs on Xmas Eve, at his ex's.

This doesn't sit right with me at all.
Can I just be told if it's right for it to not sit right with me or is this something I just have to deal with otherwise I'm being selfish?

This wouldn't bother me unless I had other reasons for suspicion.

Reading between the lines though, it sounds like you're in a relatively new relationship so he's probably letting you know rather than asking you for permission (not that he should have to anyway, but you know what I mean).

Only other issue would be if you were the OW?