Private-equity investor allegedly punches out teenager and gives him concussion at Southampton party

A charity event at a Southampton mansion went awry last weekend when the home's owner punched out a teenage guest, leaving the teen broken-nosed and concussed.

Michael Loeb, 62, owns the 16,000 square-foot home featured in Showtime's "Billions," where he hosted a July 15 fundraiser for special needs children. The "Ribs for Kids" barbecue benefiting Pop.Earth was going swimmingly -- until rowdy teenage friends of his son arrived.

Avery Arjang, 18, says Loeb got angry when an unnamed other friend got too drunk and passed out in Loeb's garage. As an ambulance was about to depart with the drunken friend, Loeb allegedly confronted Arjang, telling him to call his parents, who are well-known New York jewelers.

"Michael was furious because [the drunk teen] kind of ruined his event," Arjang told Page Six. He allegedly punched the Arjang in the face and threatened, "I'm going to f---ing kick your a--."

Arjang later arrived at Southampton Hospital, where "the police were asking me to press charges, and when they told me I broke my nose, I decided I had to press charges," Arjang said. In addition, Arjang said he was also diagnosed with a concussion.

Loeb is a well-known New York figure who worked for Time Warner before entering the private investment space as founder and CEO of Loeb Enterprises. He and his wife often host and/or participate in prominent charity fundraisers. Photos by Bloomberg from the "Ribs for Kids" barbecue (before the drama) show a lovely, upscale outdoor affair.

Arjang's lawyer, Michael Griffith, hinted at a "major lawsuit," vowing, "If Michael Loeb gave my client a bloody nose, when we get to court we're going to give him a bloody nose."