An Allston man who couldn’t resist nature’s call was arraigned yesterday for allegedly urinating out the window of a party bus travelling through Boston’s Back Bay, Suffolk County District Attorney Daniel F. Conley said.

ELAN ALEXENBERG (D.O.B. 3/4/90) was charged in the Boston Municipal Court with indecent exposure and disorderly conduct for his mid-morning antics. He was released without monetary bail.

Boston Police patrolling the area at about 9:05 a.m. spotted the blue bus and heard music blasting from its windows as it travelled down Newbury Street toward Massachusetts Avenue. As it approached a red light at Exeter Street, the officers watched as a passenger opened the right rear window, exposed himself, and urinated into the street in front of a group of pedestrians.

The officers activated their unmarked cruiser’s lights and sirens and stopped the bus. They boarded it and saw Alexenberg standing by the right rear window amid a group of about 15 other males who appeared intoxicated. The detectives escorted Alexenberg off the bus, at which point he allegedly said he was sorry for what he’d done and “didn’t mean for it to happen.”

The officers placed him under arrest. They informed the bus driver that he was free to continue on his way but recommended that he return the passengers to Woburn, whence they came.

Alexenberg was represented by attorney Brian Lenfest. He will return to court on Nov. 15.