Unperfect Marriage: Second Chance

After being betrothed to her adoptive parents’ son, Frenda knew that her life would completely change. She used to have been living independently and taking care of herself, must begin to get used to the existence of Ervan, a foreign man who she does not really know closely.
“We can’t trust anybody but you to be Ervan’s wife, Frenda.”
Her adoptive parents said those words when they asked her to marry Ervan.
And Frenda doesn’t have the power to refuse her adoptive parents’ request because she remembers the good thing they have done in her entire life. But of course, Ervan has the option to refuse their ridiculous married arrangement with a mediocre woman like her.
But, unfortunately, there was no rejection from Ervan as she had expected.
The marriage occurred two years after Frenda and Ervan knew each other well.
Ervan is handsome. He cares and always knows how to make a woman bounce with his sweet smile. There’s nothing wrong with Ervan, so it’s easy for a woman with little experience in love relationship like Frenda to fall in love with this man.
Unfortunately, one year after their marriage, Frenda found out that Ervan was cheating—he had an affair. Not once or twice, but more than six times.
A marriage that at first Frenda lived happily has turned into a hell that burns her own heart. The only thing Frenda continues to do is survive to fulfill her responsibility as an adopted child who is trying to repay her parents’ kindness.
So, she still tries to continue her marriage with Ervan. She acted as if Ervan had done nothing wrong. She chose to ignore Ervan’s infidelity, forgetting her husband’s mistakes. But, when her heart was getting used to the pain, she suddenly decided to run away and sent Ervan divorce papers as a sign that she had given up.
What made Frenda finally decide to leave? Especially when she was being pregnant secretly. When Ervan’s affair could not break through her defensive walls, what made her decision suddenly change?