Paul Anka’s “Having My Baby”.
Every Sperm is Sacred
Liberty Bell? Yeah, that’d be strange. Especially if you did the whole “IT’S… Monty Python’s Flying Circus” thing and made the squishing noises. How about we just include ALL Python songs? Even “Sit On My Face and Tell Me That You Love Me” would ruin the mood.
Also anything by Anal Cunt.
We’ve had some good threads here about bad choices for wedding songs. The most popular seems to be “I Will Always Love You” by Dolly Parton.
J Geils Band, Love Stinks
She’ll Be Commin’ Round the Mountain When She Comes…
White Wedding
Yakkity Sax on a kazoo? Right out.
Even when you’re giving oral.
Brand New Lover - Dead or Alive
That song that always plays on Benny Hill whenever they’re moving in fast motion . . .
The Empire March from Return of the Jedi
Time Is on My Side
The Internationale (unless your partner is really, you know, political)
Does Your Chewing Gum Lose Its Flavor on the Bedpost Overnight?
Iiiiiii am the man in the box!
If You See Kay … unless you’re with Kay, in which case, knock yourself out
Patches
In the Ghetto
Timothy
Wildfire
and definitely not
Volga Boatmen
For the ladies
Stop Using Sex As A Weapon
She Bop
Watching Scotty Grow
pretty much anything by Alice Cooper but especially not Only Women Bleed (especially if it applies) and Cold Ethyl (tho if that applies, you have more problems than choosing appropriate humming sex music)
if your SO freaked out while watching A CLOCKWORK ORANGE, I recommend against Singing In the Rain or Beethoven’s 9th also.
I Touch Myself by the Divinyls. It’d just be weird timing.
That, or The Police’s Every Breath You Take. Using that as your wedding song is about as stupid as using Born in the USA as a presidential re-election campaign song. 
The instrumental themes to either the Exorcist, Friday the 13th, Nightmare on Elm Street, or Halloween.
Fightin’ da ignorance.
How about Fiddle About from The Who’s Tommy?
I’m your wicked uncle Ernie
I’m glad you won’t see or hear me as I
Fiddle about, fiddle about, fiddle about
Yup. This all falls into a new category I just invented: So Stupid it HAD to Happen.
Theme songs:
Mission Impossible - unless, perhaps, you punctuated the "da da"s and "deedle da"s appropriately. 
Star Trek - The Original Series - the songstress is singing over the music with just - “ahhhhh AHHHHHH, Ah Ahh ahh ahh ahhhhhhh; aHH AHHH Ahh Ahh ahh ahh ahhhhhhh …”