Kubrick also had to tread lightly around Humbert and Lolita`s sexual relationship, which one could say is non-existent in the film (although Kubrick seems to suggest otherwise in certain scenes). One might wonder why Kubrick bothered adapting the novel if he had to tone it down so much (in fact, Kubrick later said he wouldn't have bothered making it had he known how little the censors would let him get away with), but LOLITA is still a milestone film. It's certainly a different animal from Nabakov`s book, but is brilliant in it`s own way, thanks to Kubrick`s incredible direction (I wager he never made a bad film, EYES WIDE SHUT included), and two knockout performances from James Mason and Peter Sellers.
I don`t think people realize what a risky role this was for Mason at the time, with him being best known to American audiences at Captain Nemo is Walt Disney`s version of 20,000 LEAGUES UNDER THE SEA. Humbert is a complex role, and Mason really embraces the more unseemly aspects of the character, which helps this adaptation come off as more than a watered-down version of the book. Even if we don`t see Humbert molest Lolita, we know that his intentions are the worst one could imagine, and this is a brave role which could have destroyed his career had Kubrick not been able to make the film as tasteful as he did.
As for Sellers, this came right at the beginning of his golden period, with THE PINK PANTHER being a year away. Quilty really plays to all of Sellers' gifts,, with him making him a somewhat satanic figure at times, although his death scene is so pathetic, one almost has sympathy for him- which should have been impossible given the role. Sellers and Kubrick really were a match made in heaven (artistically at least) with this leading right in to DR STRANGELOVE less than two years later- guaranteeing immortality for the both of them.