betrayed by husband, divorced when pregnant

Marrying her best friend was a dream come true for Kelly, but everything truly has a limitation.
Pierce is Kelly’s first love, but as his best friend, she knew well there was always another woman deep in his heart.
Lexi Gilbert. The woman Pierce could never forget even if he had already been arranged to marry Kelly.
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Kelly finally realized their happy marriage of the last three years was just a beautiful dream when Pierce asked for a divorce just because Lexi returned.
She could only be his best friend even if she was carrying his baby.
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Since their friendship had become a cage, Kelly chose to set him free, as well as the miserable herself.
But why then, it was Pierce who became the one who refused to move on?
To make matters worse, her devil stepbrother also domineeringly stepped in at the same time, asking her to be his.
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Her Prince Charming vs. Her Devil Stepbrother?
How could Kelly save her heart in this battle of love and hate?