The Bible refers to the bloom of youth which, generally speaking, starts around puberty and extends until the mid 20's. (The Bible indicates a male is an adult at age 30.) Indeed, even after puberty a person's youthful appearance and proportions are evident through their 20's and some even into then early 30's. Pro. 19:11 speaks of the beauty of "a man" (an adult) and that has to do with his character.
Pro. 31: 30 likewise contrasts a woman’s fleeting physical beauty to the everlasting beauty of character and moral integrity. Pro. 16:31 speaks of the beauty of old age-righteousness. In all those references from Proverbs it is clear that what makes a person truly beautiful both in the sight God and man, is their character, not their physical attributes.
Perhaps you’ve noticed that physically beautiful people can have ugly personalities. This proves that what gives us each our individual beauty is our hearts and minds. So to be drawn to physical beauty or sexual appeal can be disappointing in the long run. But being drawn to a person because of the beauty of character--this is enduring, endearing and dependable.