The Flash, Season 5

Ralph:
I've seen enough episodes of Sister, Sister to recognize a siblings' spat when I see one.

Caitlin:
So, I'm trying to help Cisco with his metahuman cure, but every time I start working on it, Killer Frost takes over and messes with my equations. [points to a whiteboard] Like this. She changed all my heterozygotes into asterisks.

Ralph:
Oh. I thought those were just tiny snowflakes. So she's not on board?

Caitlin:
No. And I don't know exactly know why.

Ralph:
Can't you just ask her?

Caitlin:
Oh, I've tried. But every time we start talking about it, she starts singing Barney's "I Love You" song.

Ralph:
Ooo, that's cold.