Wow, are the rumors ever flying between what actually happened between Chris Brown and Rihanna that eventually led to Chris Brown giving Rihanna a black eye, among other things.
First, the rumor is that Rihanna gave Chris Brown herpes after she cheated on him with some rapper. But then that rumor is refuted and another states that Chris Brown was caught flirting with Paris Hilton at the pre-Grammy party and then he received a text message from an ex-girlfriend. Rihanna lost it and, evidently, so did Chris Brown.
I'm pretty sure it wasn't one single thing that led to the beat down, but rather a handful of things that caused things to escalate to the point where they got violent.
If someone gave me herpes, yeah, I'd probably beat the crap out of them. And if someone was cheating on me, again, I'd probably give them a beat down. I'm not saying that what Chris Brown did was okay, but when someone sees red, they lose sight of consequences. I'm just sayin'.