He Plays Inappropriate Songs
We mentioned this in the intro, but your DJ doesn't have to play filthy vintage rap to offend your ears.
Depending on what kind of tunes you and your new Mr. are into, anything from hip-hop to recent top-40 hits may not be to your liking. The DJ's job is to ensure you and your guests are having a good time and are ready to dance the night away, regardless of your group's personal music tastes. Even if you and new hubby are die-hard metalheads, he can't very well spin Anthrax and Metallica all night.
You can give him a few "must have" track selections, a list of "not approved" song titles and a general theme or idea to work with, but the music is pretty much disc jockey's choice, so don't think he's going to stick with a strict list. A real, professional DJ will judge the crowd and play a mix that'll get everyone out on the dance floor, regardless of if they're used to clubs, raves or mosh pits.