Question

What makes you blush when you see the person you like?​

Answer 1

Its a fight-or-flight reaction, it comes from increased blood circulation from adrenaline when you see your crush.

Answer 2

When we are attracted to someone, blood will flow to our face, causing our cheeks to get red. This happens to mimic the orgasm effect where we get flushed. It is an evolutionary way the body tries to attract the opposite sex. This is why women wear blush.