LOVE-STARVED BRUCE WILLIS PARTIES WITH XXX GIRLS

- and he's gone middle-age crazy!

Now that the reconciliation between "Armageddon" star Bruce Willis and wife Demi Moore has fizzled, the lonely actor is chasing cheap thrills in Europe -- where three porno stars say they rebuffed him!

"Bruce is like a man cut adrift," disclosed a source close to Willis -- who's abroad filming "The Story of Us."

"He is desperately trying to cover up his terrible loneliness without Demi by acting like a man half his age. It's clear, having just celebrated his 44th birthday, he's going middle-age crazy."

Partying in Paris' Planet Hollywood, Bruce hit a new low on March 14 when he tried to pick up the porno princesses and was told flat-out by one: "You're going to need some Viagra if you want to take on the three of us!" Then the trio stormed out on the red-faced rogue.

A short while earlier, eager Bruce -- perched in the deejay booth and dressed like a teen rocker -- spotted porno stars Jill Kelly, Deven Davis and Dolly Golden dancing together.

"Bruce liked what he saw," Kelly told The ENQUIRER in an exclusive interview. "One of his bodyguards came up to Deven and Dolly and said that his boss would like 'a private show.'

"It was clear that what he meant was 'a private sex show.' By that time, Bruce knew we were all porno actresses. We went to a private room in the Planet Hollywood along with members of Bruce's security detail. Soon Bruce himself sauntered in with a big lopsided grin plastered on his face.

"He was trying to look and act very young and hip. He had on these baggy Adidas pants and a scarf around his head, with this hip-looking little beanie hat.

"It was a real hip-hop get-up and Bruce was trying to act very 'street-wise,' yelling to his buddies, 'Yo, yo, yo! Hey, waz up!'

"He came on to Deven very heavily, calling her his 'little angel' and asked us to 'perform' for the 10 or 15 people there.

"Bruce just expected us to snap to attention and do what he wanted and he wasn't even particularly nice about it. In fact, he was downright rude!

"He told us exactly what he wanted to see us do to each other in the crudest terms possible. Bruce's attitude just rubbed me the wrong way, and I let him know it.

"When it became clear to him that he wasn't going to get his way with us, he grumbled something and began to walk away.

"Deven, Dolly and I walked back out into the main part of Planet Hollywood and, shortly thereafter, Bruce came down the stairs from the private area and approached us.

"He began to banter about what he'd do with all of us sexually if we gave him half a chance, leaving nothing to the imagination. His obnoxious behavior was a real turn-off.

"I just rolled my eyes and said, 'Yeah, whatever.' "

That's when Kelly hit the "Die Hard" star with her killer line about needing Viagra.

"He replied, 'Well, let's just go back to my hotel room and find out,' " revealed Kelly.

"So, I talked it over with Deven and we both agreed that Bruce was just too gross and too arrogant for us to consider going back to his hotel and have sex with him.

"Look, if he'd acted different, if he'd had a little class, heck we probably would have had sex with him! But he was just a jerk, so we declined his offer, got up and walked out of Planet Hollywood!"

-- MICHAEL GLYNN and MARC CETNER