At nineteen and drunk he picks her off the curb.
"It's not my fault. They didn't tell me. I thought it was Kool-Aid."
"Oh, get over yourself, nobody drink that," Derek barks, and tries to hook her arm over his shoulder. She flops over him. "I was waiting. Here. For two hours. For you."
He asks her, "Why'd you never call?"
"Because I didn't have to."
She cries straight through her twentieth birthday because her flight's cancelled and her cell phone's busted and France's great and the French boys are great but she has never wanted to go home so badly in her life, and it literally almost makes her sick to be so alone.
Derek gets into a car crash when he's twenty three that dislocates his right shoulder and knocks him unconscious for three days. By the time he wakes up all the flowers she'd brought him have died and her eyes aren't red anymore, just exhausted.
"The hospital called me halfway through my psychology midterm and I thought you were dead," she says, without emotion.
He laughs wildly, "Did you stay to finish the test?"
"I was already done. As if I needed the full time. Please."
(She didn't, she fails, and she retakes the course in the spring so there won't be a B on her transcript.)
When she's twenty four she trips during practice and breaks her ankle. He drives her to the doctor's office and they say they'll have her walking in half a year, but she's never going to dance in the big leagues.
As with everything, Casey takes it hard.
To remedy the situation, Derek buys her a goldfish and names it Sushi. It perishes in the next three days. This does not make her feel any better. Dumping the bowl over his head does.
And then he kisses her, because he smells like a dirty aquarium and he knows it'll gross her out. She gets lipstick all over his face.
When he's eighty one he smacks her in the shin with the head of his cane, which he doesn't really need, but he likes it because it looks like a light-saber. She sqwaks indignantly.
"Would you give it a rest?" snaps his grandson, and shovels down another mouthful of spaghetti, "You're like some lame out-dated sitcom. Jesus Grandpa, just buy her some flowers or something."
"You're a good boy," Casey says appreciatively. Derek sticks his tongue out at her.