We've been separated for two years but been seeing each other on and off. This is the third time she has said she's moving on. I found out she was seeing someone again seven weeks ago, three weeks ago I met her to drop off our kids . That day we text each other lots and I went round and stayed that night. Next day I was rejected by her which screwed up my head, speaking to her couple of days later she's told me her heart is mine only . Next day she asked me round for sex which I didn't turn down. Two days later I went to pick up the kids but only one was with her, when I asked where my son was she said with her boyfriend, and that I knew the score!! I went mad marched up to her house and shouted through letter box what had been happening! To no avail!! Now she wants to be friends?? And spoke to me today like nothing has happened!! what would you do? I just want to hold her and my kids

I guess the fly in YOUR ointment is this b/f in more ways then one and probably she communicates her real feelings to him about you, and he disuades her. A very confused young lady is what is coming across in your post. You have to ride this out somehow and back off your contact with her for the time being until the dust settles. It is going to be hard for you to accomplish but I suggest just concentrate on your time with the kids and back off her for the time being.