Dipper raises an eyebrow at the suggestion. He thinks Chara is actually trying to help, which is... nice of them. There are many reasons Dipper doesn't want to try make-up, and the girl thing is one of them. The fact that he hates spending more time on his appearance than the time it takes to shove a hat over his messy hair is another one. Spending hours putting on make-up to look older seems like a waste of time he could spend doing anything else.

Besides, he's pretty sure his face isn't the main reason people treat him like a kid.

"It won't make me taller." And it won't make his voice lose its adolescent edge. Without those, he'll just look like a little kid wearing age make-up.