So go back in time with me to when the humans first evolved. Now as a male your god given responsibility was to make more humans because the life span was 25-30 years max and you want to spread your seed as much as possible so your instinct was to "get with" (͡° ͜ʖ ͡°) as many girls aa possible so there would be more humans on the planet. It remained instinct for thousands of years because the male brain loves novelty and naked chicks it loves new naked chicks.