Ashton Kutcher is angry about today's infidelity reports surrounding his marriage--and he's letting the world know via Twitter.

Early this morning, Star Magazine reported that an eyewitness saw Kutcher making out with a blonde that wasn't his wife of five years, Demi Moore. "Ashton had this gorgeous girl pinned against the wall, and he was totally making out with her," the eyewitness told Star. "I was shocked to see him sucking face with a girl who obviously wasn't Demi."

Star claims the star's marriage is "in danger of falling apart" after the "bombshell news." Star also quotes another source: "All along, Demi was told it would never work, that he's going to cheat," a friend tells Star. "When she finds out that it happened, she'll be devastated."