Why did this random guy on the street call me ugly?

Anonymous
I was walking with a friend and she was taking a picture of me by this giant sculpture and this gentlemen walks infront of me with his friend and says “wow she is so beautiful” looks me straight in the eyes and I smile at him and thank him and then his friend goes “I don’t see it she’s ugly bro” and walks away while his friend shakes his head at him. Like? What was the reason? He could have just walked away I wasn’t doing anything offensive.
Why did this random guy on the street call me ugly?
2 Opinion