Ok... apologies.... long story...
My partner has two incredible kids and he has shared custody with their mum. He split up with her for numerous reasons, but in the separation agreement, they put in writing that, if they met someone, they would wait 6 months before introducing them to the kids. My partner followed this to the letter, and it was even 9 months before he felt it appropriate to introduce me to his children, keeping his ex informed every step of the way. I had a face to face meeting with her first, and even communicated with her personally about any steps that were being made, such as me staying over at the house for the first time when the kids were there etc.
Now the shoe is on the other foot. At New Year, she asked to get back with my partner, he said no, soon after she "met someone" it was "serious" and this weekend she has moved him into her house. They have been together maximum two months. My partner expressed numerous times he didn't want him to meet the kids so soon and that agreement should be respected, but he found out his ex's new partner was there with the kids and had slept over when his daughter let slip on the phone.
Thoughts....?