Anthony Weiner is a douche for running around (ethereally speaking) on his old lady.
But that's NOT why he should resign. He should resign because he made up one piss-poor lie after another to cover it up. In fact, he used his position as a Congressman to get a national audience--multiple times--to further the fabrication. That's conduct unbecoming and THAT is why he should resign.
And, as big a douche as Weiner is--those people in his district who'd vote for him again are even larger douches.