The word entered regular English usage through a bad Full Metal Alchemist] anime dub in which the name of the character Gluttony] was translated as Blatany. The modern definition is thought to have arisen from association with the character's distinguishing tongue and unholy hunger.
Leviticus 18:36-38 - Thou shalt not blatanize with mankind, as with womankind: it is abomination.
Actually, don't do it with womankind, either; that stuff is nasty. And she probably won't be into it, either.
Let me tell you Bro, it's not gonna help your chances of impressing her. Not one bit.