For me, that's enough not to go back. Obviously, its up to you (and your ex).

Has he asked you to get back together, or is it because you've been invited on hols? Just wondering if you may be confusing having your lives entwined because of the kids and real romantic feelings. Kind of stirred up something, if you know what I mean. I hope that was ok to say and I've not offended.

Sounds tho, even if you dont get back together, that you and he have the basis of a good friendship, which is lovely I think. Great for the kids too!

Wish you all the best.