Hugh Hefner or Crystal Harris's dog -- it's a toss up which one's sniffed more ass at the Playboy mansion ... but one of them took last night off, we presume, for the Harris-Hefner wedding.
Ex-Playmate Crystal forced her Cavalier King Charles Spaniel, named Charles, to go black tie for the ceremony ... which was attended by a small group of family and friends.
We're not much for wedding pics ... unless there's a damn cute dog involved.
So, there ya go.
Fun fact: Most King Charles Spaniels live between 10 and 15 years. Hef's longest marriage was 10 years and change.