My son would like to get to know me. However, the custodial parents are against the idea. What should I do?

My son that I raised recently found his half brother that my ex and I gave up for adoption 15 years ago, on the internet. They wish to have a relationship and my adopted son would also like to get to know me. However, the custodial parents are against the idea. What should I do? He has already contacted me.

My only experience with

My only experience with anything remotely similar is a niece who is being raised by my former brother in law and his new wife. Visits are rare, she would like to see us more, we would like to see her. However, we just respect her parents for now and hope to have a closer relationship once she is 18. I'm always worried if we push they will not only cut off contact, but will manipulate her into not having a relationship with us when she is able.

I think Jentle's advice is good. If you don't feel you can talk with his aparents directly, perhaps a third party - a social worker or family friend can plead your case.

As an adoptive parent, they may not be ready for this. It might feel really threatening. Your/their son may be challenging them in other ways just because he is a teenager. I hope it works out, and I hope sooner rather than later.

Wow... That's gotta be just

Wow... That's gotta be just about 500 different kinds of hard. Can you ask to talk to the custodial parents? How firmly are they against it and why? Is this something where you can all put your heads together and take into account that, as a 15 year old, he's going to take matters into his own hands and maybe you should find some way to honor his wishes? Maybe they're afraid you might undermine them? Perhaps working with them on the situation could make things easier all around and help you all find acceptable compromises.

I think the hardest part would be in talking to your adopted son about the situation... on the one hand you don't want to make him feel rejected, but you also can't risk either defying his other parents' wishes or pulling the "oh, if only they would allow it" card...  

Maybe something along the lines of, "I appreciate and understand your desire to know me. I am really looking forward to getting to know you. This may not be the right time for that, let me talk to your parents and see what they think."

Honestly, I don't know the best way through this.... I would want to be very careful not to undermine their authority with him - I wouldn't want my son to feel I had let him be raised by someone I had less than full confidence in...
(Hopefully you'll get some thoughts from people who have more hands-on adoption experience.)