As good as this song is, this is a bonin' song and not a smoochin' song.
So I've thought about this far too much and I'm compiling a soundtrack now for good songs for the mood.
Smoochin' Songs
"Kiss the Girl" - The Little Mermaid Soundtrack
"Everytime We Touch" - Cascada
"Stuttering" - Ben's Brother
"Head Over Feet" - Alanis Morissette
"Kiss" - Prince (or Tom Jones's cover)
That Heavy Pettin' Time
"Something About Us" - Daft Punk
"Can't Get Enough of Your Love" - Barry White
"Let's Get It On" - Marvin Gaye
"Let's Groove" - Earth Wind and Fire
"Home" - Depeche Mode
Straight Up Fuckin' Songs
"Policy of Truth" - Depeche Mode
"Sex Bomb" - Tom Jones
"Sexual Healing" - Marvin Gaye
"The Bad Touch" - Bloodhound Gang
"Pony" - Genuwine
"The No Pants Dance" - Tupper Ware Remix Party feat. Ninja Sex Party
"You Spin Me Round (Like a Record)" - Dead or Alive
Of course this isn't the end-all, be-all list, but rather a starter. The first few songs set the mood for smoochin', and as it leads up to "Kiss" things should be heavy enough that the mood naturally gets cranked up a few more steps. I like the Marvin Gaye back-to-back set up, where "Let's Get It On" gets you to doin' the do, and following it up with "Sexual Healing" to set the rhythm of the do that you're doin'.