BRUCE WILLIS is boozing again – and his goofy antics have friends worried that his decision to start hitting the bot­tle could be disastrous!

After years of sobriety, the 57-year-old action hero stunned audiences with several loopy talk-show appearances while touting his latest movie, “A Good Day to Die Hard.”

And Willis, who has a long history of battling alcohol and drug demons, openly admitted that he’s drinking again.

“I had been sober,” the “Armageddon” star said.

“But once I realized that I wasn’t gonna run myself off the pier of life with alcohol, drinking vodka out of the bottle every day…I have wine now, mostly when I eat.”

Yet his behavior during recent TV in­terviews was so bizarre that some viewers seemed to think he’d been indulging in more than a little wine with dinner.

On the popular London-based “One Show,” Willis openly criticized his new movie. One viewer said that he “mumbled and hesitated and was gen­erally incoherent” while another blasted Willis as “a mumbling moron.”

“The Expendables” star later apol­ogized, saying: “I had a little sinking spell,” and claimed to be “jet-lagged.”

But his outrageous behavior didn’t stop there. On British TV’s “Day­break,” he did a “spit take” – and spewed water all over the floor! And during a recent appearance on the “Late Show with David Let­terman,” the kooky actor donned headgear like the pope wears. Now pals fear Willis’ boozing is out of control.

Bruce has always said that he’s an alcoholic,” noted one longtime buddy. “Well, if you’re an alcoholic, you can’t start drinking again, no mat­ter what! It doesn’t matter if it’s wine, beer or vodka.”

Willis – a dad of three with ex-wife Demi Moore and now raising 10-month-old daughter Mabel with current spouse Emma Heming – already claims to have quit boozing at least twice.

“If Bruce is drinking, it could jeopardize his mar­riage,” said his pal. “I think he needs to stop now before he gets in serious trouble.”