I use two trusty options. either alot of alcohol, or chloroform. both are very effective.
Well she is already going with you to Prom...and this could just be the crazy Australian talking...but why don't you ask her out on a proper date, have some drinks, go back to an empty house (Very important that step) and just be yourself?
Get out of here, you crazy Australian. Tricks and schemes are what we want here.