Re: The baby is mine and he does not know
You already are a home wrecker - so a little bit too late to say I don't want to be a home wrecker. You should come clean with her partner and tell him the truth which is "I was going out with your wife/gf and when I found out that she was with you (and that you were a pretty good person who stepped up to be a dad to a kid that wasn't yours), I still decided to carry on with her and we now are having a baby together. What would you like me to do from now on ? "
Then let him decide what's next and if he asks you to back off then you should.
As for whether his miserable cheating wreck of a woman decides to come clean that is up to her.
This is my quest, to follow that star
No matter how hopeless, no matter how far
To fight for the right, without question or pause
To be willing to march into Hell, for a Heavenly cause