He wakes up at night around 1:03 AM. He needed to tinkle. They were on a luxury Bus sharing a couple-seat on the upper deck, sleeper coach. AC was blowing cold air at its full capacity; the temperature was low. Scientifically speaking, one tends to take a piss more often during winter than any other season. He was drowsy, so much so that he was barely able to open his eyes completely. Feeling lazy, he had a crazy idea. It didn't seem too crazy, at that very particular moment to him. He looked at her mother, fast asleep on his side.
Then, he reaches out for the water bottle. It was provided to them by the conductor of the bus, just like other passengers. Management had also lent them a blanket, which they were supposed to share. It was a combination of some uncanny circumstances, coincidences that lead them to be in this situation. Mother was in denial at first but after some convincing and having no other option. She agreed.
The bottle was almost empty; he screws open the cap and hold the bottle's mouth right ahead of the crotch. Unzipping his pants, he grabs his erect manhood. He needed an immediate release. He tries to stuff the head-knob into the mouth of the bottle, but for him to pull this off, he needed a bottle with the mouth that was twice or perhaps thrice bigger than it was. He makes sure to cover the opening of his urethra within the mouth of the bottle and starts tinkling. The one-liter bottle gets filled up to around 70% of its volume when he stops. He puts on the cap, puts the bottle in the corner, and goes back to sleep.
The journey was supposed to be over at around 5:00-5:30 AM; that's why he didn't consider the risk factor involved with his act. About an hour later, the mother wakes up, and she is thirsty. She reaches for the water bottle and takes a large amount of the liquid in her mouth. She gulped once and realized the salty ingredient that came along. She wanted to spit out what remained in her mouth, but the window wasn't open, and she had no time to open it. She covered her mouth to keep herself from throwing up. She forced herself to take it all in, and only then she realized that she could've just opened the window.
The mother puts the cap back on and looks at her son. She takes a moment to think about what just happened. She felt silly, pranked, disgusted. But strangely happy, satiated. Deep down her heart, she thinks of her son as a grown man, a man with potential. She decides not to wake him up or tell him about the incident, but she takes another sip off the bottle and smiles right after for some reason. Putting the cap back on, she puts it back where it was and snuggles under the blanket with her son.
She closed her eyes momentarily. Unable to sleep, she opens her eyes back, looks at her son. The image of him holding the bottle and tinkling inside it starts to manifest inside her mind. Moisture starts pooling between her legs. She shoved off the morbid thoughts and turned around. Now, facing the window instead of him. She shuts her eyes, again, but to no avail. She curses herself for loving the incident and thinking of her son as a man. That's when something promising happens. Call it God's will or a fluke. She felt him move in his sleep, and he wrapped his arm around her. Cuddling her closer to himself, he poked at her bottom. She could feel the girth and hardness of his valiance. She arched her bottom out for him in response.
From here on, this can go in two different directions.
- He wakes up soon, and he starts coping a feel as well. Her mother makes sure to pretend she's asleep until the right moment. And then; shit happens.
- He didn't wake up that night until they arrive at their destination. The mother doesn't mention the bottle, but she's developed strong sexual emotions for him. The first one is quite straight forward. It's totally up to you how long you can stretch the few hours they have left. In the second situation, it could be just a start of what will lead to a morbid mother & son immoral relationship that advances further along with time.