Ex dp is the father of both our ds's (15&7). We have been separated (mostly amicably) for the past 5 years.
About 18 months ago he began seeing a work colleague and moved in together immediately. Although I didn't like her (various reasons but mainly she is only 10 years older than ds1) the dc would occasionally stay at ex dp's when I needed him to have them. (He's never had them on a regular weekend duty as he works every other weekend. But when asked he would have them occasionally at theirs and mainly he would stay at mine to watch them and go home when I got in during the evening) last November 2013 he left his new gf due to her behaviour, she drinks regularly and when drunk would become violent towards exdp. I have listened to his discussion of her behaviour towards him in disgust. He left their home and has stayed with us for the past 5 months (on the sofa) relationships with the dc have been good and they are happy to have seen their dad a lot more again. (When with his exgf he would see them for 2 x 1.5 hours twice a week at most when he picked ds2 up from school and then would drop him with me at work as he needed to get back home - he had moved 30 miles away with exgf)
Anyway (trying not to drop feed)
He has now decided to move back with his ex gf, I asked if he could babysit the dc Sunday eve, but he will only do this now if he can have them stay with him and exgf.
I am not happy with this. After listening to him being upset with her treatment towards him, the violence when she's drunk and her mood swings, I am not prepared to allow the dc to be with her. Exdp says she is fine now and won't be violent towards the dc but still I am refusing to allow them to be with her.
I know if I had been in a relationship with a man who had been violent towards me that exdp would not be happy (if I had left imaginary violent man and then returned to a such a relationship) having a person around the dc.
Am I being unreasonable in not letting her near our dc. I have said I will not be happy and will pull out all stops to not let her near them.
Sorry that was soo long!!