By Michael Glynn

Paris Hilton may be checking out of her relationship with new beau Stavros Niarchos III after some rowdy pals of the Greek shipping heir caused up to $100,000 worth of damage by trashing one of their Las Vegas hotel rooms and setting off the sprinkler system.

Even party-loving Paris, 24, was said to be livid with 20-year-old Stavros after a pillow fight escalated into a room-destroying melee at the Hard Rock Hotel.

Sources say the couple is headed for the rocks over the juvenile stunt, which triggered the hotel water works and forced other guests to evacuate in the early morning hours of Nov. 13.

“Paris has had it with Stavros after this room trashing stunt,” said a source close to the celebrity heiress. “She thinks he and his crazy buddies are way too immature for her.”

The out-of-control shenanigans took place after Paris, Stavros and friends helped Kelly Osbourne celebrate her 21st birthday party at the hotel’s trendy nightclub Body English the night before.

During the pillow fight-gone awry, one of the tables in the room was apparently tossed into the air and hit the sprinkler head on the ceiling, setting off the fire alarm, as well as the sprinklers in several other rooms in the hotel.

“I was woken up by fire alarms at about 7:30 a.m and then a half-hour later,” said a guest in a neighboring hotel room.

“As I evacuated with other people on the floor, I saw into Paris and Stavros’ room — down pillow feathers covered the carpet and every lamp was broken.

“A tall, young guy I recognized as Stavros was standing there shirtless, with white feathers in his long hair, while his bodyguard told Hard Rock representatives, ‘Why are you so upset? It’s all going to be paid for.'”

“At least four rooms suffered water damage.”

According to a hotel insider, Stavros — whose family is worth a reported $7.5 billion — could be charged as much as $100,000 for the damage.

“He had to call his father to get the credit card charge okayed,” said the insider. “And Paris, who was elsewhere when the bust-up took place, was furious with her boyfriend when she had to bail him and his buddies out of a jam with the management.

“She was overheard telling Kelly, ‘Just look at this mess! I don’t want them (The Hard Rock Hotel) to think I bring in people who do this stuff.'”

A spokesman for Paris told the Enquirer, “The man at the center of this is someone else, who bears a striking resemblance to Stavros. When they go out clubbing together in Los Angeles he is frequently mistaken for Stavros. At the time of the shenanigans Stavros was asleep in bed with Paris.”

That doesn’t mean Paris was any less angry with Stavros over this latest incident. She holds him personally responsible for what happened.

According to the Simple Life star’s friend, the act of hooliganism may be the final straw for her relationship with Stavros.

Paris — who was engaged to Greek shipping heir Paris Latsis before dating Stavros — told a pal, “I’ve had it with Greek boyfriends.”

Check out our exclusive pics of the hotel room below.