This one's for you Kari!! I don't understand the mustache craze either, but it sure looks cute on a 2 year old.
I don't think my son even knew what a mustache was, but he's been saying "mustache" ever since he got up from his nap and I fit the elastic on him to finish this.
I saw this idea while scrolling through the archives at Sew Mama Sew - from 5 Orange Potatoes. Since it would be worn by a 2 year old, I sandwiched the ends of the elastic between the 2 layers of felt because I'm guessing he would have it on backwards half the time - so this way, both sides are finished and presentable.