This is when the male is about to cum and says to the girl close your eyes and open wide. The girl agrees and does it then quickly the man diarehias orange shit into her mouth tricking her and making it look like rainbow sherbert.
John: hey mary I'm almost there
Mary: okay i'l close my mouth and open wide
John:hahaha just kdding here comes the diarehia
Mary: hahaha good rainbow sherbert, there's shit in my mouth!