If "Dependency Theory" proves correct, then someone with an unhealthy obsession of becoming an "older sister"("Luna-nee") to her "younger brother"("Nao-kun") who is willing to do ANYTHING and EVERYTHING to be that "older sister", even if it means denying her own feelings towards him as a woman ("Luna").
Plenty of ways to stave off horni other than smash, guys do it all the time, every morning. For one, getting drunk hard enough actually REDUCES libido in a person, contrary to popular belief. "Tipsy is what gets you to the door, stop drinking once you get there." -is a tip that I often got from folks that actually worked in the industry.
The problem here is, you're so set on your own interpretation, that even when the author already proved that you guessed wrong, you still couldn't believe that possibilities other than Luna Smash could've existed.