I don't think the FL ever has any feelings for Taeha. She's just doing responsibility as his wife, because the marriage was arranged by her father (especialy it seems that at the time her father arranged the marriage, she's still in her lowest low, so being with Taeha just makes her feel worse). So even if she finds out about the cheating, I don't think she'd care that much. And she's actually really pretty, she just needs more confidence (I don't blame her considering of what happened before which also destroyed that). She will "tame" Taeha and then leave him (or I hope she will )
I don't think the FL ever has any feelings for Taeha. She's just doing responsibility as his wife, because the marriage was arranged by her father (especialy it seems that at the time her father arranged the marriage, she's still in her lowest low, so being with Taeha just makes her feel worse). So even if she finds out about the cheating, I don't think she'd care that much. And she's actually really pretty, she just needs more confidence (I don't blame her considering of what happened before which also destroyed that). She will "tame" Taeha and then leave him (or I hope she will )