When approaching emminent climax whilst receiving oral sex, a man will pull out his penis and ejaculate on the "performer's" face. As she is blinded by his semen, the male then punches her in the nose and mixes the blood and semen all over her face in a mixture known, colloquially, as a "schmatz."
"Damn! Did you just see Jamal's ho? She's all bloody and spooged-- and her nose is all banged up! He really gave that bitch a good schmatz!"