I started seeing someone from work about two years ago - he had been married and has two small DCs. While not divorced, he was 'properly' separated - so living in a separate house, having DC stay over with him at weekend etc. There was definitely no overlap between me and his ex wife!
On the one hand - we have had a great relationship. He gets me completely, we have a really fun time together, I feel able to be completely myself with him. I love him and I can't imagine having to move on.
On the other - he is still not divorced and perhaps more importantly - I've still not been introduced to his DC. To be clear - I don't think at all I should be taking on a step-parenting sort of role - but I do think that that seeing his children at some weekends (even just in the role of 'Daddy's friend') should be expected by this stage.
The reason for the delay with the divorce progressing/not seeing his children etc. is that financially things are likely to be difficult - he works full time and his ex wife is part time and he is worried about the splitting of the mortgage etc. He isn't being difficult towards ex wife re withholding money or anything like that - they still have a joint account which they just haven't got around to closing. He says he doesn't want his children to have to move house (which I can understand) and he is worried about his ex moving to live nearer her parents, which would make contact harder. He wants to have more frequent contact with his DC, but ex wife is reluctant for this.
While his ex is aware that I exist, she doesn't think it's appropriate for me to spend any time with the DC until I have a meeting with her - I don't think this is a reasonable request given that things between the two of them are still really quite difficult and divorce is not yet finalised. DP also doesn't think this is reasonable, but keeps dragging his feet over formalising contact arrangements etc.
I don't have children and I am not quite yet 30 - I just increasingly think that the sensible/right thing to do is to cut my losses and withdraw myself from this situation. I don't want to but I just keep thinking that the advice I would give to a friend in this situation is to leave, and so maybe that's what I'm left with now.