Can Metta Make you Beautiful? Omg.Is this true.But what do you
mean like inner beauty? Or outer beauty? I'm more interested in outer beauty.Is there any reference in the suttas about being physically beautiful if you practice metta? 

Thank you
Metta does make you physicaly beautiful. You don't go from being super ugly, to super gorgeous. But it can improve a lot more than you might think.

Using an analogy, have you ever noticed that when you are in a realy good mood, people are more enthusiastic with you? And have you ever noticed how when you're in a bad mood, the opposite happens? We all react instinctively to other people's moods, because these moods are "written" in the facial expression, even if we're not consciously aware of "reading" these facial expressions. It's just how the human animal reacts through instinct.

Metta cultivates such high spirits of kindness, happiness and love that your facial expression becomes pleasant, loving and happy. The bitterness, anger, frustration, depression, etc, all melt, day by day, with he practice of metta. Through continued practice, that makes you more and more beautiful.

But if you don't believe me, check these photos taken before and after a meditation retreat:

http://www.shambhalamountain.org/dathun-before-and-after-photos/