Hi SFPS,
This is Turkish wrestling. It's a unique sport with unusual rules and traditions as seen by more Western standards. I don't presume to understand it all properly. But the basics seem to come down to the wrestlers getting completely oiled up before their matches. Pretty much head to toe and all points in between. This makes it harder to flip over or gain a solid grip over your opponent. Think of catching a greased pig I guess. So apparently reaching part way, or all the way, into the back or the front of the other's pants to get some good leverage over your very slippery opponent is considered completely appropriate and within the rules.
I've seen photos where the guys pull out the front waistbands of their pants so the oil can be poured inside over their crotches. Apparently the only thing worse than having your junk roughly manhandled, is for it to be manhandled when that tender skin is all dry and more prone to scratching and bruising. Ouch! haha I'll see if I can't find some pics of the oiling up process leading up to the wrestling matches that I've seen previously. I'll try to add them to future pics even if they may not look especially erotic in their own right.