Take This Waltz -- Film Description:
"Twenty-eight-year-old Margot (two-time Academy Award-nominee Michelle Williams) is happily married to Lou (Seth Rogen), a good-natured cookbook author. But when Margot meets Daniel (Luke Kirby), their mutual attraction is obvious and immediate. To make matters worse (or perhaps better), Daniel lives right across the street. The two begin spending time together and try to restrain themselves from doing things they might regret, but the sweltering Toronto summer has a way of making certain desires more urgent. There are no easy answers here, no heroes or villains. The emotional texture of the performances—perhaps most surprisingly from Rogen [...], whose depth of feeling proves as potent as his gift for comedy—only heightens the film's complex dance of love. [...]"
-- Toronto International Film Festival

Source:
"TIFF: The Festival: 2011 Films." Toronto International Film Festival. http://tiff.net/filmsandschedules/tiff/2011/.