Jealousy Incarnate
The Eternal Love
Rak Kan Panlawan
Go Ho's starry night (a short webseries. The ML sees her with other men and he gets jealous. I don't know if she falls without realizing though...)
Down With Love has a strong element of that. I really loved this little drama.
Familiar wife: the ML has to see her with another man for a good chunk of the show but she's always conscious of her feelings for him.