Žižek on A Short Film About Love

How does he [Tomek] capture Maria's desire? The answer, of course, resides in the very purity and absolute intensity of his love: he acts as the pure S*, the subject whose desire is so burning that it cannot be translated into any concrete demand - this very intensity, because of which his desire can only express itself in the guise of a refusal of any demand ('I want nothing from you'), is what makes him irresistible. This second metaphoric substitution is not simply symmetrical to the first one: their difference hinges on the opposition of 'to have' and 'to be'. In the first case, we are in the dimension of having (the loved one doesn't know what he has in himself that makes him worthy of the other's love, so, in order to escape this deadlock, he returns love), whereas in the second case, the loving is (becomes) the beloved object on account of the sheer intensity of the love.
What one has to reject here is the notion that Tomek's love for Maria is authentic and pure, spiritual, elevated above vulgar sensuality, whereas Maria, disturbed by this purity, intends to humiliate him and later changes her attitude out of a feeling of guilt. It is, on the contrary, Tomek's love that is fundamentally false, a narcissistic attitude of idealization whose necessary obverse is a barely concieved lethal dimension. That is to say, A Short Film About Love should be read against the background of slasher films, in which a man observes and harasses a woman who traumatizes him, finally attacking her with a knife: it is a kind of introverted slasher in which the man, instead of striking at the woman, deals a blow to himself. The reason his love for Maria is not genuine does not reside in its 'impure' character: the murderous burst of self-inflicted violence is the inherent obverse of its very 'purity'. This inauthenticity of his love is corroborated by his inability to undergo the experience of desublimation, of the splitting between the woman qua impossible-idealized Thing and the flesh-and-blood woman who offers herself to him - that is, by the way this experience sets in motion the murderous passage à l'acte: the measure of true love is precisely the capacity to withstand such a splitting. Maria's love for him, in contrast, is fully authentic: from the moment Tomek tells her he wants nothing from her, true love - which, as Lacan points out, is always a love returned - is here, and her humiliation of Tomek is merely a desperate attempt to disavow this fact.

* This S has a line running through it from top right to bottom left although I can't find the symbol on my keyboard or in Word.

~ from The Žižek Reader, Chapter 8: There is No Sexual Relationship (p. 197 - 198)
[edited by Elizabeth and Edmond Wright]