Sorry, that's supposed to be Hell, not He'll.
I've read the book and watched the movie. I think Jack was the one who was molested. He hates himself. The drinking is to control his thoughts. He's all screwed up in there. He was probably attracted to Al which was a friend in the book work got him the job at the hotel. He was spending all his time with him. He has repressed homosesexual tendencies ( which he has tangled up with the emotions of being molested) and that's why he hates himself and strikes out. In the book when he beats up a student the guy cries out " you hate me because you know..." or something close too that. It's not in the movie. But the student he beat up and lost his job over was probably gay. On top of it when ever Jack describes him physically its like he's attracted to him. He describes his tan arms, golden skin and the blond hairs on them. And the hair falling over his brow.. He compares him to Robert Redford. He's everything Jack isn't and isn't that what we are usually attracted to? It's scares Jack on a very subconscious level. Deep down the wife suspects the truth too. That's why she sees the fellatio. The Hotel is messing with her. Jack hasn't molested Danny but he's terrified deep down that he will. The Hotel represents and basically is a den of depravity. Its demon possessed and if you die there you're trapped. The ghosts are aware and do things with and to each other. Most people can't see. Poor Danny can. Think the seven level of He'll. But without punishment. Dante's inferno. Any depraved thought is possible there. Things a lot worse than Jack thinks homosexuality is. I think Jack definitely had some of the Shine. That's why the Hotel got to him. When he drank that first drink in the Hotel bar he sold his soul. That's when he was completely possessed. Before that it was just breaking him down. There never was any real alcohol. It's all an illusion. He just gave up. He was slowly driven insane. The Father's Love scene is a hint at his worst fear coming true. The Hotel is basically saying "you give yourself to me and do what I want or I'm going to make you molest your child." A part of Jack probably wanted to mentally check out after that. He probably thought being drunk and giving was better better than hurting his son. I think he realized at that point the Hotel wanted to kill them all. What do you think?