It gets somewhat trickier when two homosexuals, in the privacy of their own home, want to adopt a child, which to my way of thinking, is criminal child abuse.
I would want those same men prevented from adopting a child for exactly those activities they admit to doing in the privacy of their own home.
Pinging some Christian lawyers for their input.
It is to my way of thinking also. And I'm willing to be called a "homophobe" by my libertarian compatriots for that position. (shrugs) Oh, well.
Ideally, I'd prefer to see adoption law follow the Biblical model -- which is to try to place the orphan within the extended family, to the maximum extent possible. Also the tradition of the Godfather would be a great tradition to resurrect (I'm a godfather myself) -- there are some excellent Church, Family, and other such Non-Governmental solutions to some of these problems.
Admittedly, there might be a few "gay uncles" in some families who might come up on the docket, but at least that way you avoid the problem of homosexuals specifically hunting for children to adopt.
There would be details to be worked out; but I think when we start with the Biblical model, we're at least working from good general principles.