"Ooooh. What does Stitches like Gossping about?" Sunny asks as she tries the tea. More bitter than she was used to, but she wasn't used to that much sugar in her tea. Her mom wanted her to be a healthy pegasus, so she only let Sunny have a certain amount of sweets on days other than Nightmare Night.
It's also due to the fact that Sunny gets hyper when hopped up on sugar.