It's funny when people comment on self gratification as being gay.
Myself? I can do it, I am the type that is able to bite toenails etc. and I have seen how flexible I can get, I would be able to at least lick my own penis but maybe not get my lips around it, if Iwas able to likely not get further than the head.
Would I do it? Nah, I find normal masturbating to be fine and easy, sucking myself off would be far to painful and awkward keeping my body in such a position. To be honest it wouldn't give enough pleasure to be worth the effort. Also added to those physical reasons I dislike the idea of sucking myself off, I leave such things for another to do even if currently rarely.