The “National Enquirer” claims that BRUCE WILLIS got in ASHTON KUTCHER’S face and delivered a verbal beatdown that reduced Ashton to tears.

A source says, quote, “Ashton kept avoiding Bruce’s calls and texts, but finally agreed to meet his wife’s ex-husband at a private location.  Bruce was livid!

“He reamed Ashton for his cheating . . . and humiliating not just ex-wife Demi, but his three daughters as well.  He went at Ashton full force, giving him no time to make excuses for his embarrassing behavior, demanding that he get his act together FAST!

“Ashton finally broke down in tears, weeping uncontrollably as he begged for forgiveness . . . [And he vowed], ‘I will NEVER, EVER cheat again!’”

Meanwhile, “In Touch Weekly” says that Demi wasn’t entirely innocent.  Sources say she had a fling with 27-year-old actor BEN HOLLINGSWORTH.

Apparently, she and Ashton were guiding his career . . . and in 2009 they even got him a part on the CW show “The Beautiful Life” . . . which Ashton was producing.

As for the sex, a source says, quote, “[Ben] said she was really hot and she took care of him.”  You can read more about this here.