Kalabha Kadhalan (2006)

A sister in law (Akshaya) falls in love with her brother in law Akhilan (Arya). But he refuses her because he adores his wife (Renuka Menon) and he never would cheat on her. He hides all facts to his wife in order to protect her. Finally the sister in law commits suicide after a tragedy that becomes the climax of the film.