Ashton Kutcher and Demi Moore's six-year union may be coming to an end.

Amid new tabloid reports of infidelity on Kutcher's behalf, the spouses have taken a break from their normally lovey-dovey tweets -- a strong indicator that their relationship is on the rocks.

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Moore shared a quote from Greek philosopher Epictetus on September 23, 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 a forlorn picture of herself with the caption: "I see through you."

Earlier in the month, Moore told her Twitter followers that she was "trying to find the light I lost.” On September 9, she added: “'ve got your own back."

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Adding to speculation that Kutcher and Moore have separated? The pair spent their sixth wedding anniversary -- September 23 -- apart.

While Kutcher, 33, whooped it up with his former That '70s Show costar Danny Masterson in San Diego, his wife, 48, was busy promoting the short film she directed for Lifetime's upcoming anthology, Five.

Moore -- who shocked onlookers with her rail-thin appearance at the Five premiere in NYC -- is also pulling out of pre-arranged public engagements.

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"Demi was supposed to attend David LaChappelle's art show in West Hollywood Tuesday night," a source tells Us Weekly. "She pulled out of the event last minute."

The actors' reps have yet to comment.

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