this happened to me, my biological father ditched my mom when he found out she was pregnant. 18 years later when I was a freshman in college, my mom found him on facebook and started talking to him. he ended up saying that he wasn't really sure if he wanted to talk to me, since he didn't want his family to find out about me. he has 2 sons (my 2 half brothers) that i've never met and probably never will. for now I just haven't talked to him at all because I don't feel like dealing with him, but sometimes I think about how great it would be to blow his cover to his family...

Let me get this straight... your dad is abandoning you... because he doesn't want to own up to his responsibilities as a father and adoptive father? FYL.

Truly horrible. I can scarcely imagine the pain you must be feeling. Ultimately, though, it's going to be his loss. Karma has a way of doing exactly the right thing in such circumstances. Please be kind and take the best possible care of yourself. Your father is an ass of the worst kind.

I agree with #8

I am sorry at this sad story. My frank opinion is that he doesn't deserve you.

Your father asked you not to contact him, so if you do it could be considered harrassment. That said, he DID NOT tell you not to talk to his wife and children. You can talk to them all you want and if they want proof that you are his, show them a copy of your birth certificate. You're an adult, you ought to be able to do that no problem. There is no reason you shouldn't have a relationship with your half-siblings.

agreed with number 8

Make friends with his kids and make sure to ask them about their family life. When they gush about their wonderful father tell them that you envy them because your father is and asshole that won't have anything to do with you. Get yourself invited over for dinner. Might be a low way to handle it, but his other family deserves to know that he is a coward that will run and hide rather than stand up and do what is right.

If I were you, I'd wait until your "father" was at work, and then show up at his house, and introduce yourself to his new family. Then, leave before he gets home. Stay in touch with his new wife and kids, but don't talk to him. Explain it to them, telling them what he said, and that you want to respect his wished to not contact him again, but that there's no reason you can't get to know your step-mother and siblings.

I agree with everyone. Find one of the siblings or the wife and explain to them.