A sex song is a song that you can listen to whilst having sex. Normally, it would have good rhythm that you could move your hips too, and it could possibly have sexual lyrics. The lyrics do not necessarily have to be appropriate for the "occasion", just as long as it sounds sexy.
1. Glory Box by Portishead is the best sex song ever.
2. No Ordinary Love by Deftones is a totally awesome song to have sex to.