Two BLACK INK CREW reality stars got into a HUGE FIGHT - inside Diddy's $40M Star Island MANSION.
Diddy opened up his party to celebrity friends - to ring in the new year in style. And well, that was a mistake.
In addition to celebrities - a lot of REALITY STAR RATCHETS were at the event - and it POPPED OFF.
According to MediaTakeOut.com's snitches, Rah Ali and Sky from BLACK INK CREW got into a fight - and Rah Ali beat Sky BLOODY.
An insider explained, "They broke up sh*t all in Diddy's house, got blood on stuff. It was real messed up. In a house like [Diddy's] they probably did $100K in damage."
No word yet from Diddy about the F*CKERY that went down last night . . .