Any shows where the male lead is in love with his sister-in-law who is the female lead and then gets his chance because she divorces his brother? She then falls for her ex-brother-in-law.  Maybe the brother and family try to keep them apart, but then get past that and end up together.

Not a TV show but a movie: Addicted. The the plot is not exactly like what you've described, but it is about a man who loves his late brother's wife. It has some mature scenes, so please be aware.

Spring Day (2005) - not married, more of older brother is in a relationship with FL.

A lot like Addicted Movie suggested above, try Secret Love (2010, Movie)

 kura2ninja:

Not a TV show but a movie: Addicted. The the plot is not exactly like what you've described, but it is about a man who loves his late brother's wife. It has some mature scenes, so please be aware.

+1 for this movie (one of my all time fav) - its so interesting because the story took quite a circle and some twist