Demi Moore cheating attack ashton kutcher salon sunglasses fight

It seems the stress is getting to Demi Moore ...

Demi hid behind her hands as she left a West Hollywood nail salon Friday morning, shielding her super skinny body as she made her wait to a chauffeur-driven car.

Moore screamed obscenities, stunning on-lookers.

Our photographer tells us: "Demi was upset. I was just standing on the sidewalk, trying to get a few shots of her and she didn't want any part of it. She definitely wants OUT of the spotlight."

It appears the stress of infidelity accusations may be affecting Ashton too ... Wednesday night in New York (during a trip WITHOUT Demi), Kutcher addressed the crowd at the GQ Gentleman's Ball, dropping four-letter words and downing a few glasses of wine, according to reports.

Are these two headed for a breakup, a breakdown or both?