Star and Ariel
"You haven't had chocolate? You are learning all the wrong things apparently. When we're done here we'll fix that." Star might be the worst influence in the world when it came to teaching her about new things.
"Oh and dancing, we should do dancing." Star nodded decisively, Ariel needed to learn all the fun things that teenagers did.
"Fire?" Star was picking her second marshmallow off her stick to eat. "Um, I'm bad at the whole chemical reaction explanation thing but it's fire. When you get too much heat things start to burn. In Mewni we use it to cook and heat the castle and all the huts and cottages and things. Well okay we also use magic for that but fire is easier. "