Jeonnampyeongwa Donggeojungimnida

Hee-Young and Seo-Won get divorced after a long marriage. However, due to her fertility problems and other reasons, Hee-Young promises to continue living together while they hide their divorce. The two are able to date freely, and even feel comfortable enough to give each other dating advice. Then one day, Hee-Young gets pregnant with her boyfriend's child. (Source: Naver, translated)