By behaving in the way you do, which seems civilised, you only encourage the flies. Just be yourself for a change, let your bollocks swing in and out of the shorts, while downing a can of SB or other top notch lager and let nature take it's course. Actually, maybe the he-fly may want his cut of drink, which will prove expensive in the long run, while the she-fly is keen on your nads and wouldn't find your festive display in the least offensive...