"
it's such a pity, a boy so pretty
With an ugly heart
Maybe
It's sad that someone who is so physically attractive is not a nice person. She's basically telling her ex boyfriend that she figured out that he's just a pretty face and there's nothing behind that pretty face. Yes, he is one of the most good looking men she's met, but all one of the biggest a**hats she's ever met who doesn't really care about people. Essentially an ex that wasn't emotionally invested in the relationship.