Used to describe a woman of Caucasian decent (a white woman) that is fairly nice looking.
1st guy: Damn! She look hella good.
2nd guy: I know! Damn, that bitch is BMK! Black Man's Kryptonite! I gotta hit that!
1st guy: Yep, I would tap that ass! I'm gettin' weak right now!
1st girl: Gurl look at that bitch!
2nd girl: Yeah, there goes another brotha. Lost to that BMK.
1st girl: Yep, ole funky ass white bitch!