Having watched many gay-related movies, Keillers Park felt as though I had already seen it. We have a closeted gay man, Peter, who's engaged to a woman, and ends up being propositioned by a gay man, Nassim, in a park, they have sex and fall in love. Peter's fiance "discovers" that he's gay when he tries to penetrate her from the behind, because that is, apparently, a sure giveaway. Straight men NEVER have anal sex with women! Of course not...
It seems as though you're supposed to feel bad for the Peter, but he comes off as a bit of a jerk. The only thing that makes you feel bad for him is the fact that his family disowns him for being gay. Other than that, he isn't exactly likable. Though, as far as the story goes, it's hard to tell if it's an intended distaste or poor character writing.
I wouldn't call this movie entirely unoriginal, however. On top of this story line there is a shred of originality. The overlying theme is a murder mystery, and you're plagued with the question of whether or not Peter murdered his lover.