Kutcher and Moore have been together since 2003. Credit: Getty Images

The couple - who are notorious for their standard of over-sharing via social media site Twitter - have been suspiciously quiet of late, amid rumours of infidelity on Kutcher's behalf.

On their sixth wedding anniversary (on September 24th), instead of Tweeting anniversary wishes at each other, Moore shared a quote from Greek philosopher Epictetus on Twitter, writing "When we are offended at any man's fault, turn to yourself and study your own failings. Then you will forget your anger."

Three days later, Moore posted an unhappy looking photo of herself with her eyes closed, with the caption: "I see through you."

Demi tweeted this picture of herself on September 27. Credit: Twitter

The first waves of discontent were visible earlier this month, with Moore telling her Twitter followers that she was “trying to find the light I lost.”

Perhaps the nail in the coffin for the good-looking duo was spending their sixth wedding anniversary apart.

Kutcher, 33, was in San Diego with former co-star Danny Masterson, while Moore, 48, was busy promoting a short film she directed, ‘Five’.