Because everyone should know what it's like to get punched in the face and have a black eye, a couple of hot chicks who'd never had the pleasure decided to take turns knocking the piss out of each other. According to a follow-up posted in the description for the video on YouTube, neither of the girls got a black eye out of the deal, just some minor swelling but now they both (kind of) know what the dude who posed for the cover of Pantera's Vulgar Display of Power felt like.

It's not clear as to whether or not alcohol was involved, because I didn't see any in the video but come on, there's no way they were sober when the did this. But then again, I never claimed to totally understand women.