Rob had a record of sleepwalking since he was seven years old. During sleep, he gets out of bed, goes to the bathroom, looks into the mirror. The light of the bathroom hits his face, reflected, goes to the mirror, reflected, travels through his cornea, hits his retina. His own image, composed by light waves of different intensity and wavelength, gets translated by the cone cells and rod cells to a bunch of electro-chemical impulses, also known as neural signals. Finally (actually it's just the beginning), the neural signals arrive at the brain through the optic nerve.
Through obscure paths, the neural signals finally arrive at the back of the brain, the visual cortex. In a summer when I was a kid, I fell down with the back of my head hitting the playground, I saw a lot of shiny stars out of nowhere. You see, it's because of the weird stimuli received by the visual cortex.
The visual cortex gives Rob the ability to “see” the image, the visual sense , when he is awake. But Rob is sleeping now. So “who” is “seeing” the Rob in the mirror, if not Rob? Maybe it's just his trained brain, doing what it's been trained to do. It's like a trained neural network, Google Brain, it can differentiate a cat from a dog in an image, but you can't say it's capable of feeling, it's not “seeing” the image, it's just responding to the image with a huge amount of pre-trained rules.
So when sleepwalking, the human mind becomes an artificial brain, the human becomes an android. It's said a sleepwalking human can do certain complicated tasks better than being awake. Because machines are superior to humans in many areas, they introduce minimum errors, simply due to the fact that they don't need to deal with the boggled human feelings.
Ana, Rob's girlfriend, is used to his sleepwalking. To her it's just like Rob being woken up by the urge to pee in the middle of the night. In her memory, Rob never went out of the house when he was sleepwalking. He simply walked around in the house, mostly to the bathroom, then went back to bed automatically, just like going to pee in the middle of the night.
It's another night, supposedly a normal night. Ana and Rob go to the bedroom, they get undressed, flirting, showering, intercourse, another showering. Now they want to sleep.
So they sleep.
After two hours’ sleep, the android Rob wakes up. He gently moves himself out of the quilt, puts his feet on the ground, without any noise. He silently walks to the toilet, he becomes a good damping system, like a cat. Rob doesn't look at the mirror this time, instead, he takes a shower again.
In the last ten years, there were 18 recorded cases of patients with amnestic engagement in sexual behavior while asleep, which was called “sexual behavior during sleep” (SBS). The number 18 is gonna become 19 soon.
Rob comes back from the bathroom, he gently wakes Ana up, with a subtle yet charming smile on his face. This is the first time he deliberately wakes her up during sleepwalking. Ana isn't mad at being woken up, because Rob is so gentle and caring, Rob's facial expression attracts her, even though Rob hasn't said anything. Maybe being silent is a key to become attracting. And I don't know if a sleepwalking human is capable of talking.
Ana gets Rob. She feels the smell of the shower gel, refreshing. She surrounds him with her arms, Rob kisses, Ana kisses back, they kiss. They feel each other's breath, skin, hair, anywhere. They look at each other's eyes. Rob's eyes show a combination of childishness, shyness, lust, and many more.
Of course, they went further.
Ana feels so great.
She will eventually realize she was having sex with someone in his dream, she has been having an affair with an android.
But who cares? Rob is never going to find out.