When someone first announces to the world that they are gay, and them over the next several months begins outwardly acting more and more gay in their mannerisms and interests. This acceleration of gayness is known as homomentum.
When Frank first came out of the closet a few months ago, it was kind of a surprise. But since then, he has started watching Glee, reading all the Twilight books, and listening to Nickelback. He sure is building up a lot of homomentum! Next thing you know, he will be rooting for the Pittsburgh Steelers.