Tom and Dan's Relationship
The intimacy between Tom and Dan was way more powerful than a kissing or sex scene, whether they were shouting at each other or just talking softly so as interesting as that would be, it's unnecessary. I think Tom was still very attracted to Dan for several reasons: (1) Tom was a very reserved and shy guy yet it seems he revealed a lot more about himself to Dan than he probably did with others (for example, talking about the expectations and need to conform in the town where he was from); (2) Even though they only had a one-night stand, that one night obviously had a very lasting and strong effect on Tom. He said he remembered every detail about what was said and done. He even remembered exactly what he was wearing. Why would someone remember such details unless it it was important to him at the time; (3) When Tom is dancing with the older woman, he declines to have sex with her yet the person he goes to for comfort right after that scene is Dan. As another poster mentioned, this is an extremely powerful moment in the film. Tom crawls on his knees, sobbing, to Dan's lap. Dan too is very affectionate but then makes a move for the keys. It appears Tom is truly hurt by this action and sees it as just another betrayal. He lashes out at Dan saying "Is this what you want?" holding up the keys, as if to say you want these keys more than me? I think Tom was more furious and hurt at that moment, than any other moment in the film.
On a lighter note, even though the film was dark, powerful, etc., there were several very cute moments between the two of them, despite Dan being tied up almost the entire time: (1) When Dan asks what college Tom went to and Tom says that NASA gets all their people from his school; (2) the entire exchange between Dan and Tom when Dan tried to wake him to tell him he needed to use the bathroom; (3) Dan chattering away while Tom is trying to watch the game and (4) when Tom is about to let Dan go, he almost affectionately brushes Dan's hair aside to unwrap the tape. He was so gentle, it was almost sweet.
I could easily see the two of them in a relationship under different circumstances.