A sexual act in which a man, when he's nearing climax, puts on a wig of dreadlocks (This has the best effect when the wig comes on while her eyes are closed, so she gets the full effect when she opens her eyes.) And just as she's thinking "What the fuck?" you pull out and cum all over her while singing the "Oy yoy yoy. Oy yoy yoy yoy. Oy yoy yoy, yoy yoy yoy yoy yoy" section of the chorus of Buffalo Soldier by Bob Marley.
She completely freaked out when he did the buffalo soldier as he spooged on her tits.