The stalker is coded to possibly be a closeted and homophobic gay character. He refers regularly to homosexuals, and even seduces one - before killing him. Though he is obsessed with a Hollywood starlet, and frequently mentions wanting to have sex with her (using his gigantic organ), he is not seen to have an actual girlfriend. Because the starlet is written as being the diva type and is far older than he, it makes it unclear whether he actually is interested in her sexually or as an unobtainable diva icon that is safe for him to want.
In any case, homosexual are mentioned in a non-negative light by the starlet, and the stalker refers to them regularly in derogatory terms.
This book might put some off by being in the form of many letters back and forth between the characters. But the basic plot was captured in the movie version.