Christian Slater could be facing a summer in the slammer . . . the Hollywood star was arrested last week for allegedly groping a woman while under the influence of alcohol.

The actor and his new girlfriend were reportedly having an argument in a New York grocery store when Slater approached a woman and grabbed her bottom.

Slater, who has previously spent three months in Sing Sing prison for attacking his then girlfriend and throwing a police officer down a flight of stairs, vigorously denied the charges, claiming the unknown New York woman had fabricated the entire encounter.

The alleged "Grocery Groper" had to endure the indignity of an overnight stay in a police station, not to mention a few paparazzi snaps of him looking tired and emotional