Perhaps some people are missing the point of this thread here?
I personally think it would be great if the two boys got together and had a relationship as brothers. 'Whether or not the *birthparents* are involved depends on alot of things. Have these boys led sheltered lives? Were their adoptive parents open and aboveboard about their unusual backgrounds? Are these two young men prepared to meet parents that are not exactly Leave It To Beaver? We need to be realistic!
As birth parents, I would tread softly. Many people could be hurt, shocked, mortified. 'Count and recount your priorities as to why you are doing this. There will not be any turning back!
And it seems to me that if two people obviously realize beforehand that they >could not< be fit parents, why not be sterilized? The situtation is obviously not going to change, so why bring innocents into a difficult and unusual situation??
I do not post on AD often, only when I feel that I have something to offer. Good luck on whatever you decide to do.
Warmly, Lantana
Hopefully to hear the updates soon
And we will give you all new updates once we hear from Doug 
for update your post here.
I look forward to hearing how things turn out for you.