Sapai Part Time (2006)

Napat is a beautiful and smart woman. Her mother is suffering from kidney disease, which requires a lot of money to pay for the hospital bills. She also needs to pay the fees for her younger sister’s studies. Since she thinks all men are bad, she tricks them into falling in love with her and then takes off with their money.
Wai is a widower and a single dad. He never wantedto marry again after his wife died. Wai’s son falls in love with Napat, but Wai is against it because he knows she’s just tricking him. So Wai hires Napat to be his wife part time, that way his son will stop messing with her. Meanwhile, Napat’s sister falls in love with Wai’s son.
(Source: MyDramaList)