In an apparent attempt to end the scathing headlines that the allegations have drawn, U.S. Rep. Anthony Weiner, a Democrat, apologized repeatedly in a half-hour news conference for lying - but said he would not resign from the House of Representatives.
Weiner insisted that he had never 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.
"This was me doing a dumb thing, and doing it repeatedly, and lying about it," he said.
Weiner, 46, married Hillary Rodham Clinton aide Huma Abedin last July, with former President Bill Clinton officiating. Abedin was born in the U.S.; her father was of Indian descent, and her mother was from Pakistan. Before his marriage, Weiner had been known as one of New York's most eligible bachelors.
He said Monday that 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.
It was unclear how Weiner's admission of his online activities would affect his career. Shortly after his announcement, Rep. Nancy Pelosi, the minority leader of the House, called for an ethics committee investigation to determine if Weiner had broken House rules. Weiner said he would cooperate with an investigation.
A member of congress for 14 years, Weiner gained a national profile last year supporting liberal provision of President Barack Obama's health care reform bill.
Republican opposition to that reform bill is one reason Obama and fellow Democrats could face tougher races during the 2012 congressional and presidential races.
A conservative website, which last week started the furor over the photo of the congressman's bulging underpants sent from Weiner's Twitter account, on Monday posted new photos purportedly from a second woman who said she received shirtless shots of the congressman.
Weiner had earlier said of the underwear photo that his account was hacked and that he'd hired a lawyer and a private security firm to investigate the incident.
Weiner called the underpants photo a joke and a "hugely regrettable mistake."
Meanwhile, ABC News said Monday it planned to air an interview with a Texas woman, Meagan Broussard, who claims to be one of the women who exchanged messages with Weiner. The 26-year-old single mother said she has dozens of emails, Facebook messages and cell phone logs that document more than a month of flirting that started on April 20.
BigGovernment.com, the website run by conservative activist Andrew Breitbart, had posted the latest photos and said they were in a cache of intimate online photographs, chats and email exchanges the woman claimed to have. The website did not identify the woman.
One photo showed Weiner on a couch with two cats nearby. The website said Weiner sent the photo using the email@example.com account with the subject line "Me and the pussys."
The celebrity website RadarOnline.com said a woman claimed to have 200 sexually explicit messages from Weiner through a Facebook account that Weiner no longer uses. It was not clear whether the woman who claimed to have the new photo was the person who claimed to have received the text messages.
The photo showing Weiner shirtless was reminiscent of a photo of former Rep. Chris Lee, a New York Republican who resigned from office earlier this year after a shirtless photo he sent a woman on Craig's List became public. A Democrat won his seat.
Weiner began his career as a legislative assistant to then-Rep. Chuck Schumer, who is now the state's senior senator. He was elected to the New York City Council before winning Schumer's House seat in 1998, representing parts of Brooklyn and Queens.