Romantic relationships is about people ritualizing the act of fucking. What we call love is nothing more but the process before the dick enters the pussy. We have created a narrative around it because we want to hide how raw and animalistic we are. We created love so that we can separate ourselves from other animals.

Humans have long infancy and toddlerhood. A strong erotic bond or infatuation between man and woman normally lasts a considerably longer than until the next morning. That bond has a biological function: it keeps the man around long enough to ensure the survival of his helpless small children whose mother could not take care of them on her own. Infatuation is a perfectly normal biological response of our species. (It is amusing when people appeal to the animal kingdom to argue that one practice or another is "natural". The animal kingdom is marked with a mind-blowing variety of animals occupying vastly different ecological niches. Human nature is best deduced by watching humans and to some degree our closest cousins but with some reservations.)

Erotic love is transient, however, and as societal pressures have changed from enforcing lifelong marriage, we can observe that divorce has become commonplace. I think the average marriage that ends in divorce lasts about one decade give or take a couple of years. When erotic bond weakens with age and too much familiarity, many people choose to stay together nonetheless. That's because there is an emotion called attachment at play.

All in all, we are a bunch of apes with pedophelic tendencies that really want to fuck but are too cowards and hypocrites to admit it.

I think you used the wrong term there. Pedophilia is sexual desire directed at prepubescent children. Ephebophilia is the term you are (hopefully) looking after. I agree that it is perfectly normal to find a teenaged girl fully developed girl attractive on a purely physical level. I'm a middle-aged man and I'd find even the typical 17-year old too psychologically immature to consider having a relationship with.