Just as how I've dreamed about the exact mental and emotional states of an extremely depressed and suicidal person, I have also dreamed the final missing piece of the puzzle when it comes to attraction dynamics.
Specifically, my dream on my 20th birthday answers the question: "At what exact point in the conversation/activity between two mutually attracted people of the opposite sex spontaneously decide to do that?"
When they have become close enough to feel each other's warmth, connected enough to feel each others presence, they will automatically feel/smell each other's pheromones and inhale their hormones.
When that happens, something in their brain pops, resulting in a mental state full of fireworks, flowers, pink skies, and unicorns. There's no way to think rationally in this mental state. Due to the release and inhalation of each other's pheromones, both of them will become instantly turned on, and their minds would start to wonder how great would it be if their tongues would touch each other.
I guess there's no need for me to describe the next scenes, eh? Just watch romance dramas on tv if you still don't know haha.
There's also the risk of having an awful breath that the experience would become an instant turn off lol. If that's the case, then there's no need to let them smell your breath, since that's just a shortcut anyway.
You'd know it when the room/atmosphere suddenly feels hotter and more smelly than usual, as if you can suddenly feel/smell the essence of the other person. Most likely, they would feel the same, but if they don't, a few intimate touches here and there would do the trick.
Nope, I refuse to elaborate and explain any further. I doubt that any of my explanations can compare to your very imaginative mind anyway.
So now that we have completed the entire puzzle of attraction dynamics, let's summarize it properly:
Attraction usually begins in the first few seconds with the physical attraction (mental explosion), intensified with emotional attraction (stomach butterflies), heightened with sensual attraction (racing heart and temperature), then instantly triggered by pheromones and hormones (cringe smell), leading to an almost irresistible urge to do something (run away?), with the male usually making the first move. (NIGURENDAYO!)
This set biological and psychological processes form our so-called "Attraction System" in our body, just like the "Nervous System" or the "Cardiovascular System". This Attraction System is very connected with the Reproductive System, allowing it to do its thing, so we can say that its main purpose is for reproduction, alongside socialization.
(Insert INFP's awfully cringe but cute conclusion about love and such)
Another mystery, SOLVED!
"Weeks ago, I have solved the puzzle of suicide and just now I have resolved the puzzle of attraction. What's the next puzzle?"
"From what started as a question of 'why are these elementary gradeschoolers so thirsty that they already have a hundred ex-girlfriends and boyfriends', finally ends with an answer of 'biology'."
"So far, research haven't found any way to resist and defend against attraction. For now, the best thing we can do is to accept it, but not do anything about it, just like how we poop, but not touch our poo."