"I can't even talk to my ex about it - she just denies everything. So you see it's just not really possible. I'd need to know that she was sorry for her behaviour and understood it was wrong so I'd know it wouldn't happen again."
That's what C is for. You want her to show remorse because you want to be able to trust her again. Your resentment didn't "go away" you just buried it the first time. Deal with it once and for all. If you don't, regardless of who you're with, you're going to have the need for them to be "remorseful" for every mistake they make. You're not going to do it intentionally, but it will come out.
If at the very least, maybe you need to take care of that in IC for yourself.
I know, maybe you're right and some of that resentment would carry forward into future relationships in ways I wouldn't expect. I might see if I can sort some out for myself.
I don't think it's worth taking me ex with me - as gnosis said, stay away. She referred to as toxic on my other thread by more than one person.
