The question comes into a category of problems that all pose the same conundrum -- catharsis vs. propagation. Similar issues are porno usage and the publicity of dramatic events like the Columbine school massacre. Does doing the action (fantasizing, publicizing; in short, exposing the mind to the idea) tend to defuse the danger of adverse events happening or does it excite people to do the adverse thing? Or both, and if so, in what ratio?

This is a great conundrum; some polling-type psychological studies have attempted to resolve it, but I doubt that there's any real regular answer. For one thing, I think it relates to both the intelligence and the self-control of the person in question. If he is of very low intelligence OR low self-control, thinking the thought (doing the same as in the fantasy or porno, or killing his horrid school bullies and their friends, etc.) will make him jealous of doing the thing and he will be looking for his chance to bring the fantasy into reality. If his intelligence OR self-control is fairly high, he will think, I can have a nice quiet fantasy (or get excited about this news story and then let it pass) and discharge this thought and there is even less reason to do the real thing.

So, Cat, it all comes down to self knowledge. Are you whipping yourself up with such fantasies or defusing yourself? I am in the school of thought that holds the word epithumeo, translated as lust, means actual covetousness rather than mere fantasy, so to me there is nothing prohibited about any sexual fantasy per se. Only if it induces true lust in you, the urge to plan to do the action or the tacit permission to do it "spontaneously" if opportunity knocks, should you suppress the fantasy.

Of course, if your YF does not have a reciprocal fantasy about you and is not egging you on to become physically intimate, then as a Christian you should be experiencing minimal temptation anyways. It would not be in the least wise loving to start putting moves on the boy and surely the holy spirit will inform your judgment that he is to be left alone. Anyone who is having the "egging on" problem can start a new thread.