Pam is staying overnight at Jim's place, on a couch. The couch is old and barely comfortable, but she is tired enough not to care. It seems that right now she could fall asleep standing up.
Jim already went to bed in his own room. It's quiet. It seems like everyone in the world is asleep. Pam lays on her back thinking about Jim. It's a bit chilly, so maybe she should go upstairs and ask for an additional blanket or something.
She is wearing his black t-shirt and it smells nice. It's exciting being so close to Jim; Pam could imagine that he was embracing her right now. Pam's hand slips into her panties and she feels that she is aroused. How little does it take? She slides her middle finger between her folds, imagining that it is Jim, who is touching her ever so gently. Pam imagines that he came to her in the dark, without any words and now it is the tip of his tongue on her clit and his fingers inside her.
Somewhere outside a dog barks loudly. Pam shuddered and her thoughts returned to reality. She should definitely get one more blanket until it is too late.
Pam stood up and considered putting on her trousers, but decided not to. There was something borderline appropriate, yet very daring about letting Jim see her almost naked, wearing only his t-shirt and briefs.
She went up to the second floor, trying to move as quietly as possible for some bizarre reason. The door to Jim's room was slightly open. She was just going to knock, when she heard some strange but rather familiar noises that made her stop.
Pam felt, that she should leave as it could end embarrassingly for her and uncomfortable for Jim, but she absolutely could not. Additionally she was afraid that she might stumble on something while going back and he will notice her presence. Therefore, it seemed that the best way to handle this situation was to stay. Right?
Jim was sitting on his bed, his back pressed against the wall. It was hard to see anything, but she could hear him breathing fast. His right hand was definitely moving in a distinctive way suggesting that he was pleasuring himself.
"That is completely unethical. I should not..."
Yet she did not stop watching. It felt so wrong, violating his privacy. However, at the same time, she was curious to see everything. If only it was a little brighter outside, then she could see his…
"Now I'm a freak. I am a peeping Tom. Even worse, I am peeping Pam!"
She was following Jim's every move, catching every quiet moan.
Every second Pam dreaded that he might find out that she is here. She was terrified to death by this idea. How would he react? He would be pissed at her and never talk to her again. But maybe, just maybe, he would stand up from his bed and come to her, then take her in his arms, throw on the bed and fuck her rough until she scream his name and loses her mind in orgasmic agony. Or, perhaps, just invite her to join him. That would be scary. Most likely, he would make a joke about this whole situation. Pam doubted that there is a joke in the world that could make it less awkward.
Jim's hand was moving along the shaft of his cock. Right now, it was moving slowly and he was clearly enjoying himself. She fixed her eyes on him, noticing every slight movement, imagining what it would feel like to touch him.
Pam's breasts were so sensitive right now she could feel fabric sliding over her nipples as she was breathing. It was nice, but far from satisfying. She wanted Jim's hands to fondle her breasts and his mouth to suck on her nipples. Her vagina was aching with desire, longing for penetration.
It was hard to breathe quietly. As soon as Pam started thinking and trying to control this process, it became impossible and she was almost gasping for air. She dreaded that he might hear her. But at the same time Pam desperately wanted to have sex, as she never did before. It was hard to retain sanity and refrain from doing something stupid. Perhaps, the only thing that was stopping her from going for it was that she was afraid that he would be disappointed.

Jim heard her steps when it was too late to hide. So he pretended that he didn't notice anything. Truth be told, he never intended for this to happen. He waited for a long time for her to fall asleep and just forgot to close the door properly. Probably.
When Pam appeared he was almost finished, but now he was sort of forced to go on. Knowing that Pam was near was intoxicating and driving him crazy. He wanted to be with her so badly that it was nearly impossible to pretend that he didn't notice her. Jim tried doing everything slowly but it did not help a bit. Soon he came.
Jim wasn't mad at Pam for peeping. At the end of the day, it's not the most common thing for a girl of your dreams to hide in the dark to watch you jerk off.