The Bull is the lover of the Hotwife in a Cuckold relationship. He always has a much larger cock than the cuckold, one of the many humiliating factors for the cuckold. The Bull is also often black (Big Black Cock).
The cuckold might be enlisted to suck the Bull’s cock to make it hard for his Hotwife (fluffing) or have to clean the Bull’s cock afterwards, including his cum.
Not all cuckolds are afforded such a gift of the Bull’s cock or cum. It is a distinct honor to be permitted to touch the Bull’s dick and balls.