Hot boy ổi loạn - "Rebellious Hot Boy"* or officially in English, "Lost in Paradise"
(*Short for: Hot boy nổi loạn và câu chuyện về thằng Cười, cô gái điếm và con vịt - "Rebellious Hot Boy and the Story of Cười, the Prostitute and the Duck")
From the IMDb:
http://www.imdb.com/title/tt2043880/
Not my favourite of all favourites, but I just really love this movie. Just happy and sad, cheerful and heartbreaking, and also some scenes and dialogues could be quite an eyeopener and make you think and probably actually better understand a few groups that the societies prefer to ignore or worse, shun.
Oh, it's a Vietnamese film if you haven't figured it out quickly enough. This film is considered to be the first successful one of its genre (homosexuality and prostitution) and was well-received by the Vietnamese population. So, it's quite a big progress for a country that long pretends that the homosexuals do not exist (the regime tends to leave them alone nowadays).