The Double (2013)

Simon is a timid man scratching out an isolated existence in an indifferent world. He is overlooked at work, scorned by his mother, ignored by the woman of his dreams, and feeling powerless to change any of these things. The arrival of new co-worker James upsets the balance. James is both Simon's exact physical double and his opposite otherwise: he's a confident, charismatic ladies' man. To Simon's horror, James slowly starts taking over his life.