When you go down on a bitch when she's in full menstruation. Your face is clown red after the bloody cunnilingus, thus you've kissed the clown - "Clown's Kiss"
Originating somewhere in latin america (viral vid) translated from "el beso del payaso"
1. Damn man brah, did you bite your lip, or did you just kiss the clown?
2. I inadvertantly gave my bitch a clown's kiss, had no clue she was surfing the satanic wave!