Rumor mills have been churning, trying to figure out what went wrong in the six-year marriage between Demi Moore and Ashton Kutcher, who are speculated to have been quietly separated a few months ago.

Apparently, Ashton cheated on Demi with a 23-year-old woman, identified as Sara Leal, last weekend, on the eve of their sixth wedding anniversary. Reports suggest that Sara is preparing for a tell-all interview, provided she gets paid a fortune and has already met with an attorney.

According to a close associate of Demi, the actress believes Kutcher has sex addict issues, but he won't agree to get help or any kind of counseling, the Chicago Sun Times reported.

TheDirty.com published an email on Sept. 26, from someone who said she was a friend of the alleged mistress. The email reads:

Nik, I'm going to be straight to the point. I'm a female who works at who happens to be friends with Sara Leal, probably not after this. I'm sick to my stomach over what happen last Friday night. Like most people on earth I worshiped Ashton Kutcher and Demi Moore until Ashton Kutcher f****d my friend Sara Leal at 4:30AM technically Saturday morning in his room on the 12 floor at the Hardrock Hotel in San Diego. Ashton Kutcher told Sara Leal that him and Demi Moore are separated and the public doesn't know yet. Smooth line Ashton, she was going to f**k you anyway. Nik if you want to verify any of this just call Sara Leal yourself or ask Deena Omari. Better yet subpoena Ashton's bodyguard who took her phone before she came into the room.

Reports of Kutcher's extramarital flings are nothing new, though he always denied them in the past. The 33-year-old actor's brief affair with Brittany Jones, 21, whom he allegedly met at a Los Angeles area bowling alley, emerged in 2010; although it didn't exactly rock his marriage.

It appears that Demi, who is 15 years older than Kutcher, was aware of her straying husband for quite some time but was determined to offer him help with counseling.

In recent public appearances, Demi has looked gaunt with an unusually skinny figure. While she is known for an obsession with her body, she appeared to be stressed out and overtly cautious of herself.

She hit the news a couple of weeks ago, by tweeting semi-nude photographs of herself, stirring up a discussion among the public. Demi uploaded a topless photo of herself, taken in front of a bathroom mirror which exposes her bare back. Remember.....you've got your own back, Moore wrote in the picture caption.

When a follower tweeted to ask the purpose of releasing a semi-naked portrait, Moore tweeted back, To remember to be your own best friend to find light and protection from within yourself.

Does that smell like insecurity and a probable divorce?