BENDER. An ironical word used in conversation by flash people; as where one party affirms or professes any thing which the other believes to be false or insincere, the latter expresses his incredulity by exclaiming, Bender! or, if one asks another to do any act which the latter considers unreasonable or impracticable, he replies, O, yes, I'll do it— Bender ; meaning, by the addition of the last word, that, in fact, he will do no such thing.
--From Grose's classical dictionary of the vulgar tongue--
That's really clever, not (Bender?).