The Gun Club - Sex Beat
Whale - I'll Do Ya....and also Kickin'....and also Pay For Me....and also...*sigh* jsut buy the album "We Care"
The Cranes - Watersong (good slow, seductive, haunting foreplay music)
Nine Inch Nails - Warm Place (same as above)
An April March - Wicked Game (I like their version better)
Fantastic Plastic Machine - You Must Learn All Night Long
The Cramps - Hypno-Sex-Ray, Sinners, Daisies Up Your Butterfly
Ella Fitzgerald - Summertime
The MC5 - Let Me Try (another slow foreplay/seduction one) and Lookin' At You
X - Beyond and Back (lyrics aren't quite appropriate, but it has a very f*ckable sound)
I find most versions of Fever are good for this kind of thing. Also, if I had to choose one complete, non-mixed cd which would keep the sensual mood consistent, it would probably be most anything by Portishead, just because it stays smooth and deep and velvety for the most part, even if it is mournful.
If you're not familiar with any of the above, I highly reccommend downloading them and giving them a listen.....and having sex to them RIGHT NOW!
And if you feel guilty, you can run out and buy them right after.