|Sometimes you won't need this for people to know.|
There are several aspects to Lavender Linguistics, so named for an apparent association of the colour lavender (it's a shade of purple for any blokes who refuse to admit they know colours) with the gay community.
Of course the lexicon of the gay community will be different as it would be amongst any social circle, and even within those circles there would be a variance in the lexicon.
Just like in criminal circles, amongst gay circles (which technically were illegal at one time), there used to be a requirement for cant slang. Cant is a jargon which attempts to mislead listeners who are not members of the group.
One of the most popular versions of this slang was Polari, which came from many sources, including sailors, circus staff (carnies), and actors with some Italian, Gypsy and Yiddish words thrown in for good measure.
Although Polari fell out of popular usage after the '60s, various studies later began to evaluate the speech of homosexuals.
Several reasons for that fabulous accent have been suggested. Amongst homosexual males, a desire to copy one's peers or identify themselves as a part of that group through speech is akin to people softening their accent in a formal setting.
It's been proposed that gay men speak "effeminately" in order to emulate women, thus distancing themselves from heterosexual males. Some have even suggested that gay men will make use of code-switching while speaking in order to gauge how gay somebody is. Of course, these are all theories and just as not everybody from a certain place speaks with a certain accent, not every homosexual will talk differently. You may not even be able to tell unless you have very good gaydar...