The context of the following conversation is Riley was jealous of Sydney's good looks so she made fun of Sydney when they sang.:
Riley says It was fun making fun of Sydney when she was singing..
The friend responds I actually don't think she's a bad singer..
Riley responds She isn't. But I'm still going to make fun of her..
The friend responds Why are you doing that?.
Riley responds I'm jealous of how beautiful she is. I guess that's why I'm doing it..
The friend responds That doesn't sound like a good reason to do it..