"Gender is the range of physical, biological, mental and behavioral characteristics pertaining to, and differentiating between, masculinity and femininity." (wikipedia)
While RB may be a biological male, she is considered to be female from the cultural perspective. Her official documents, psychological state and physical appearance (for the most part), all point to her as being a female. RB's identification to being a female since birth is characterized as gender identity disorder.
The question as to whether a guy is considered to be homosexual for fucking a post op transsexual, would be largely semantics. Simplistically, homosexuality can be defined as sexual attraction to the same sex/gender. Again, depending on which definition of gender (biological vs culture) you can argue that a person is/is not a homosexual.
Personally, I feel homosexuality is better defined by the sexual attraction to the masculinity/feminine traits. Ask yourself if you would be sexually attracted to a woman who looks like a man.
And would you be sexually attracted to a biological man, ie. transsexual, who looks like a woman?
If you never found out about her history, you'd be going on about your life happy to have scored a hot chick.
I doubt the agenda of this thread was to call RB out for not having full disclosure in the WW. RB's backpage ad states in no uncertain terms that she is a post op transsexual. Besides, it doesn't take a genius to notice that some of RB's physical traits are still masculine.
What this looks like is SL started this thread to amuse some of his fellow brethren. It's not that bad passing a funny remark or two in the WW, but to put someone on the spot by starting a new thread......that's entertainment at RB's expense and going overboard. Arguably, RB's best response is to ignore this thread and let the topic die on its own. But anything she has to say will likely be dissected and used to instigate more response. It's a game/entertainment for some of you guys, but toying with someone else's emotions on a board she relies on for income.......that's a low form of entertainment....