What is "trinogamy," please? Do you mean a relationship between three people-- a triad?
To answer your question, or at least to attempt to, there are many threads here on triad relationships. Whether they are gay or not might not be specified, but we have had gay people discuss their issues here. I find it usually doesn't make too much of a difference what identity one takes with such things. People are people, love is love, and we are all trying to figure this poly thing out.
You might want to try doing a search for "triads," "vees," "queer," "homosexual," or anything else that looks interesting.
If you ask a specific question or bring up a specific topic, that might help us help you, also.