The word has entered the language through the porn industry, in a direct line from Japanese. Bukkakeru is a Japanese verb meaning "to dash (slosh) (water) on a person or in a person's face." In Japan Bukkakeru movies are highly stylised events where sometimes dozens of men ejaculate, in succession, on the face of a single girl.
1. Bukake videos feature prominently in my extensive porn collection.
2. My darling, may I relieve my building orgasm with a spot of bukake?