LUST

¹lust
Pronunciation: 'l&st
Function: noun
Etymology: Middle English, from Old English; akin to Old High German lust pleasure and perhaps to Latin lascivus wanton
1 obsolete a : PLEASURE, DELIGHT b : personal inclination : WISH
2 : usually intense or unbridled sexual desire : LASCIVIOUSNESS
3 a : an intense longing : CRAVING b : ENTHUSIASM, EAGERNESS

This is defined from http://www.webster.com and here's another one from Microsoft Encarta Dictionary Tools:

lust [lust]
n
1. sexual desire: the strong physical desire to have sex with somebody, usually without associated feelings of love or affection

2. eagerness: great eagerness or enthusiasm for something
* the lust for power

[Old English , “pleasure, desire.” Ultimately, from an Indo-European word meaning “to be eager,” which is also the ancestor of English lascivious.]

It is more blunt in the Encarta, but regardless where and how it's defined, lust is lust: an intense sexual craving for someone. Intense. Sexual. Painful. Craving. Scary. Very, very scary.

Especially if the object of your passion is just near you, yet so far. The feeling is so strong that you want to fuck him or be fucked silly. You watch him from afar and wonder how his hands would feel touching your body...wondering how his lips would feel on your own lips...wondering how his tongue would feel caressing your skin...wondering how his body would feel moving against yours...wondering how he would feel inside you...wondering if he would fulfill all your fantasies and give you ecstasy...wondering when after all the passion has been spent if you would still want him to do you until you scream for him to stop and when he stopped you wonder if you still have the yearning to scream for him to start all over...

And you're left with that...wondering. Because you know for a fact that this is not going to happen in real life. You're just in your own dream world with him as the center of your desires. Only in your deepest and darkest delusions would you ever experience sexual gratification. Then when you're done dreaming all you feel is sexual frustration because you know that deep in the recesses of your mind that you can't have him...not in the way you want to.