Don't know what to do about baby's father!

Fiona
I'm 19w6d and separated from the father of my baby when I was about 8weeks after he told me he still had feelings for his ex, (decided it would be too stressful on me which in return would cause stress for baby and with this being my first and being 35 didn't want). 2 weeks after we broke up he was hooking up with someone else (not his ex) and is now living with her and she is now about 8weeks pregnant with his baby. I have hardly heard from him and when I have its been to ask about names and who my midwife is so they don't use the same ones. No one in my family wants him involved but I don't want to be someone who tells the father he can't be involved. I just don't know what to do! I just want to do what's right for my baby.