If magic was real, that's the first magic spell girls would want to learn, once they hit puberty. For boys it'd be the cock-enlarging spell.
1.) Boy's would more likely want to learn the "Hold it Back for an hour or so spell."
2.) I've never read the books and I wasn't a fan of any of the movies but holy**** her last name is actually lovegood... there is no real reason for her not to bimbofy herself.