WASHINGTON – Rep. David Wu, D-Ore., announced Tuesday he would resign from Congress, following allegations of sexual misconduct with a teenage girl.

The resignation announcement came in the wake of a report last week that the teenage daughter of a longtime friend and campaign donor called Wu’s office earlier this year to accuse him of an unwanted sexual encounter over Thanksgiving. Wu, 56, acknowledged the incident to his aides but said it was consensual, the Portland Oregonian reported.

On Monday, House Minority Leader Nancy Pelosi, D-Calif., called for a formal ethics investigation. By Tuesday, Wu, a seven-term member of Congress, said he would resign his post.

“I cannot care for my family the way I wish while serving in Congress and fighting these very serious allegations,” Wu said in a statement. “The wellbeing of my children must come before anything else.”

The sex scandal is the second in as many months to rock Democrats in Congress. In June, Rep. Anthony Weiner, D-N.Y., stepped down after he admitted to sending lewd photos to women online.

A third congressman, Rep. Christopher Lee, R-N.Y., resigned earlier this year after flirtatious emails and shirtless photos of himself that he sent to a woman on Craigslist were made public.

The allegations against Wu, the first Chinese-American to serve in the House of Representatives, are only his latest troubles. Earlier this year, Wu admitted to seeking medical help for mental health troubles. At one point in 2010, he sent his aides photos of himself in a tiger costume that have since become public. After his re-election last fall, several of his staff members resigned.