So a couple of days ago I watched Do começo ao fim (2009). And I've been thinking it over ever since.
For those who don't recognize the title, it concerns a brazilian movie whose trailer has been making the rounds. The movie tells the story of two half-brothers (they have the same mother) by the names Francisco and Thomás who enter into a sexual/romantic relationship later in life. The tag line reads as follows: "To understand this love, one has to turn the world upside down" (Para entender esse amor é preciso virar o mundo pelo avesso).
( MAJOR SPOILERS AHEAD )