This is comes from the inside sleeve of (Per)versions of love and hate:

(see book list for full details)

“Why, when we are desperately in love, do we endlessly block the union with our love object? Why do we often destroy what we love most? Why do we search out the impossible object – is it that we desire things because they are unavailable, and therefore, to keep the desire alive, we need to prevent the fulfilment?”