Say what you will, there is a long lasting, tried and true tradition of dudes wearing tights when competing in the grappling arts/sports. I wore'em in high wrestling, Jesse the Body Ventura wor'em and, yeah, now you see Rafael Mendes sporting them in the video we're featuring here. So, there. They're totally cool and masculine and all that stuff.
If you're going to receive the tutelage of anyone on how to best pass the guard, you can do no wrong following that of Rafa Mendes. He and his bro, Guilherme, are two of the most dominant athletes in the BJJ world in recent years. Although, the two compete primarily in the gi, Rafa has two ADCC championships (2009, 2011) to his name, which is huge (really, more of a world title in no-gi than a gold from the relatively new IBJJF No-Gi Worlds). Bottom line - he knows what he's doing and you will do yourself some serious good by watching this clip.