Heh, he's also pretty dang huge which helps show being at least partially non-human. It took me awhile to realize that his metal jaw is /probably/ covering up tusks.
I don't know about it being specifically red orcs, though. They're big on sex, but their biggest target seems to be fighting and strength more than that - particularly if their warchief is a paragon of their beliefs!
Granted, Tank does seem to like fighting as well, so the theory still stands. Or well, at least he's reasonably concluded that 'this is the one thing I'm good at' and sticks with it, haha.
Being bullied fits any group, though - humans tend to dislike nonhumans, and both of the orc tribes we've interacted with are very hesitant about there being humans about, so being seen as 'the other race' and not being the brightest bulb himself means he's likely to run into problems everywhere.
(Of course, /part/ of this might be that I play a dominant top myself, so I don't know how he rolls in other situations, haha)
Tank is awesome.