'Star Wars' actor McGregor, 46 has now gone public with his relationship with American actress Winstead, 32.
"It is hard for her to believe him," a source says.
And his 51-year-old French wife is 'convinced' that despite his denials he did cheat on her with attractive brunette Winstead.
The couple were married for 22 years and according to reports the Scottish born actor told his wife that he was in love with Winstead back in May which led to the breakdown of their union.
However, the French beauty is reportedly still struggling to believe him, and is finding the situation very tough on both herself and their four children.
A source said: "Eve is sure Ewan and Mary were together before he confessed his feelings for her. It is hard for her to believe him."
The story erupted after McGregor was spotted kissing Winstead back in October inside a London café.
The pair has since gone public with their romance and are believed to have set-up a home together.
It is understood McGregor has denied having an affair behind his wife's back.
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