While checking some freebie links this morning I noticed that at freereadfeed they have a pull down menu and gay/lesbian is one of the breakdown sections under 'mixed' category. Thought I'd post to let you who are looking specifically for this genre know.
To sort go to 'view genres', then 'pick from a list'.
http://www.freereadfeed.com/
Also separate section at EReaderIQ
http://www.ereaderiq.com/