Wide World of Ass- Bad-boy actor Christian Slater was busted early yesterday on the upper East Side after he allegedly squeezed the butt of a woman almost the same age as his mother, police said.

Slater staggered out of a taxi and groped the 52-year-old woman’s buttocks on Second Ave. at 93rd St. shortly after 2 a.m., cops said.

His victim – who had no idea that the hand on her bottom belonged to a Broadway star – wasn’t flattered and called 911, police said.

Minutes later, Slater, 35, who is appearing in “The Glass Menagerie,” was arrested a block away.

“This is bull—-!” Slater whined to cops as they handcuffed him, a police source said.

“I didn’t do anything,” he fumed. “I’m suing you! I’m suing the Police Department! I’m suing everybody!”

Hours later, Slater, who shot to fame after playing teen rebels on the big screen in 1989’s “Heathers” and 1990’s “Pump Up the Volume,” was escorted in handcuffs out of the 19th Precinct stationhouse.

“This is bull—-!” he said again.

Charged with sexual abuse and forcible touching, both misdemeanors, the actor faces up to a year behind bars.

But that didn’t stop Slater from wowing the audience at the Ethel Barrymore Theater last night.

The star appeared a tad nervous when he walked onstage alone at the start of the show, but two rounds of applause quickly calmed him.

He even managed to poke fun at his problems, pinching the air while playing a character stumbling home drunk.

“We were more surprised and more than grateful that he performed,” said Chris Spavins, 49, a Toronto publisher. “This man has great stamina. He’s a star.”

Last month, a Manhattan judge dismissed a forcible touching charge against a fabric merchant who patted a customer’s behind. But while patting is not a crime, grabbing, squeezing or pinching is, the judge ruled.

Slater “had been drinking, and he grabbed her butt,” a police source said. “That’s sexual harassment.”

Slater was released without bail from Manhattan Criminal Court in plenty of time to make last night’s 7 p.m. curtain.

“This situation is the result of a misunderstanding,” said Slater’s publicist Evelyn Karamanos. “We are hopeful that this will be resolved shortly.”

The bizarre bust was the latest in a long list of run-ins between cops and Slater, who a decade ago did stints in a drug rehab center and prison for drunken driving, kicking a cop in the head and carrying an unlicensed handgun at Kennedy Airport.

He was arguing with a female companion early yesterday when he allegedly pinched the victim’s rump, authorities said.

“Stop! What are you doing?” Slater’s friend yelled at him before storming away, a law enforcement source said.

On Monday night, patrons at Iggy’s bar, on Second Ave. between 75th and 76th Sts., said Slater got into a scrape with some Marines who tried to take his photo.

Slater’s mother, Mary Jo Slater, 59, a Hollywood casting director, begged reporters in April to stop writing negative stories about her son.

He’s a rebel

Born Aug. 18, 1969, in New York to an actor father and casting director mother. His parents divorced when he was 5.

At age 9, he appeared in “The Music Man” on Broadway. At 14, he was starring in off-Broadway plays and the TV soap opera “Ryan’s Hope.”

He was allegedly abusing cocaine at age 15.

He starred as a teen killer in the 1989 dark comedy “Heathers.” He romanced Winona Ryder and Patricia Arquette.

In 1989, he spent 10 days in jail on a DWI charge.

In 1994, he was busted at Kennedy Airport for carrying a pistol in his luggage.

Three years later, he was busted by the LAPD for pummeling his girlfriend, kicking a building worker in the stomach and trying to grab a cop’s gun.

In 2003, he got nine stitches to close a gash on his head after his wife, TV producer Ryan Haddon, bashed him with a glass in a Las Vegas hotel room.

In February, he was cast to play opposite Jessica Lange in “The Glass Menagerie” on Broadway.