Not only is sex the number one search term on the Internet, it's what everyone is searching for in this material world. Sex is the prototype of all material enjoyment. Along with eating, sleeping, and defense, sex is counted as one of the four basic drives of every soul in every material body. Krishna conscious teachings have much to say on the topic—what its purpose is, how it relates to the original consciousness of the self, and how to avoid being ruled by it.
The very first teaching of Krishna consciousness is that we are not our bodies; we are spiritual beings temporarily within material bodies. No amount of material pleasure can give us true happiness because we're not material—we're spiritual. We can only really be fulfilled when our goal is spiritual happiness.
Ironically, while sex is the highest material pleasure, it can diminish our capacity to experience the highest enjoyment there is—ananda, the uninterrupted bliss that comes as a result of reawakening our spiritual consciousness and entering into a relationship with Krishna, the source of all joy.