Residents of a northern Philadelphia neighborhood say hundreds of teenagers began having sex and peeing everywhere after a summer block party turned into a free-for-all.

Residents say the crowd of marauding, procreating teenagers were in the neighborhood attending a radio station-sponsored free concert in a nearby plaza.

"My entire house was peed on, people were having sex two feet in front of my children and everyone was drunk that day," a Northern Liberties resident told NBC Philadelphia.

"There was a lot of young people in the back, underage drinking, staggering around drunk, urinating on my garage," another neighbor told NBC.

Another terrified homeowner told the Daily News she witnessed hundreds of teens just drop trou.

According to NBC, one resident began recording two teenagers who were having sex in the open. When she asked them to stop, they ignored her and apparently continued on for another 40 minutes.

Blaming the concert's apparent lack of security and porta potties, the residents are now trying to get the radio station to pay to clean up the damage.

The station put out a statement apologizing for "any of our fans who may have had a less than enjoyable experience at this past weekend's block party."

[screengrab via NBC Philadelphia]