Back story. My ex and I were together and had a baby. He left but came back numerous times asking to try again all whilst having other girls on the side. Late January this year he was still asking to have a baby with me but I said no. Things went sour and we finally went our seperate ways. Due to my job he has majority of custody of our child. Fast forward to tonight. My son is at creche, has been dropped off by a female and is being picked up by said female. I see her doing this and proceed to ask who she is and why she has MY child. Worst part is as she signed him in only she can leave with him. So I watch her walk out my child in her arms crying for me. We go outside where she tells me she is my exes partner and now lives with him( past month) They met online maybe 2-3 months ago and apparently she has been caring for my son solely for days at a time whilst my ex works away. Honestly, wtf! I dont know her from a bar of soap. I then had my ex blast abuse at me from the minesite saying how dare I?!?! What would you do. Im pretty level headed but I am heated!!