Dan Savage used to talk a lot (well, still does) in his Stranger column (Savage Love, syndicated) about the predominance of gay personal ads seeking "straight-acting" men.
He had a great audio piece in This American Life quite a few years ago. Here is the real Audio link, Savage's piece is Part 4, if you want to skip ahead.
http://www.thislife.org/ra/46.ram
The whole show is called "Sissies"