I think this is totally unacceptable. I don't think he introduced her as his girlfriend, just his friend, but my 6 year old still knew it wasn't right. The first thing he said when he came home on Monday evening was 'Mummy, we went to Tom's house'. I asked who Tom was and eventually my exh told me 'it's Sarah's little boy'. WTF!!! I've been suspicious of her for a few months but he always denied having any feelings for her or seeing her. Even now he still won't admit it, but he won't deny it either, so that tells me he IS seeing her. In the end I said to him, all you have to say is Yes or No, but he wouldn't answer me. At least I finally know why he left!!!
So basically, Monday he picks the kids up from me and school (they are 2, 4 and 6), takes them to a soft play place where she just happens to be with her 2 kids. Then they all go off to her HOUSE!!! And then all out together to ASK for dinner. OMG what is he thinking. I'm still in total shock. He's not thinking about anyone apart from himself. Our children are still hoping daddy will come home!!!