Washington ? After days of denials, a choked-up Rep. Anthony Weiner confessed Monday that he tweeted a photo of his bulging underpants to a young woman, and he also admitted to “inappropriate” exchanges with six women before and after he got married. He apologized for lying but said he would not resign.

“This was me doing a dumb thing and doing it repeatedly and lying about it,” the 46-year-old New York Democrat after a week of double-entendre headlines and late-night wisecracks full of Weiner jokes.

House Democratic leader Nancy Pelosi immediately called for an ethics committee investigation into whether Weiner broke House rules.

The congressman, who was widely expected to run for mayor of New York in 2013, said at a half-hour news conference that he had never personally met any of the women he corresponded with online and sometimes via telephone and was not even sure of their ages. He also said he had never had sex outside of his marriage.

He said he did not feel the scandal affected his work as a lawmaker but would understand if his constituents decided not to re-elect him. “I’m going to work very hard to win back their trust,” he said.

Weiner said he used his home computer and personal Blackberry, not government computers, in his exchanges with the women. But that may not protect him from House rules that say a member “shall conduct himself at all times in a manner that shall reflect creditably on the House.”

The House ethics committee on numerous occasions has cited that general rule in finding a member violated standards of conduct.

Weiner said over and over that he had made “terrible mistakes” and done “a very dumb thing” for which he bore complete responsibility, and he apologized repeatedly to his wife, Huma Abedin.

“My wife is a remarkable woman. She’s not responsible for any of this,” he said. “I apologize to her very deeply.”

Abedin did not attend his news conference, but Weiner said they would not be separating over the scandal.

The scandal unfolded more than a week ago when a conservative website reported that a photo of a man’s crotch had been sent from Weiner’s Twitter account to a college student in Seattle. For days, Weiner claimed that he hadn’t sent the photo and that he was the victim of a hacker. But he caused guffaws when he said that he couldn’t say with “certitude” that the underwear shot was not a picture of him.

The scandal escalated when the website BigGovernment.com, run by conservative activist Andrew Breitbart, posted photos purportedly from a second woman who said she received shirtless shots of the congressman. The site said the pictures were in a cache of intimate online photographs, chats and email exchanges the woman claimed to have. The website did not identify the woman.