When Morgan lifted her arm to shield her face from the sun, Alexa could see that underneath her Ivivva tank top she was wearing a sports bra. A training bra, their mother called those, embarrassingly, and Alexa felt a surge of tenderness for her little sister, because she seemed to be training for a race for which she hadn’t yet registered. How long had it been since she and Morgan had done something alone together? Too long.

“Did you break up with Tyler?” Morgan asked. “Or did he break up with you?”

“Getting right to it, huh?” Alexa sipped her straw-less water.

“Well, did you?”

“Technically, yes,” said Alexa. Their food arrived, and for a few minutes they were busy and silent, eating. Alexa offered the street corn to Morgan, who shook her head violently.

“I don’t like Tyler that much,” said Morgan.

“No? Why not?”

Morgan dipped a fry into ketchup and considered this question. “I just don’t think he seems very nice all the time.”

Alexa was almost seven when Morgan was born. The year Morgan turned six and entered elementary school Alexa was already ensconced at the middle school, wearing a bra and getting noticed for her well-put-together outfits. That was the year the crop top came back, and Alexa got dress-coded more than once. She’d come home from school, tugging off the T-shirt they’d given her at the nurses’ office, and there Morgan would be, wearing her certified Disney Anna dress and wig and singing “Do You Want to Build a Snowman?” at the top of her phlegmatic lungs.

In one year Morgan will be the age Alexa was when she first had a boyfriend (an ill-fated romance, please don’t remind her); in two, the age when she sneak-watched Fifty Shades of Gray with Destiny. (Their mothers had dropped them at Cinemagic for what the mothers thought was the evening showing of the second SpongeBob movie: Sponge Out of Water.) She supposed she hadn’t given her little sister enough credit for maturing all of these years—for having her own, sometimes possibly anguished, interior life.

“No,” agreed Alexa. “He’s not very nice all the time.”

“Is that why you broke up with him?”

After Fifty Shades, emerging from the lobby into the parking lot, Alexa and Destiny were shell-shocked, unable to meet each other’s eyes. Neither would ever admit it, but both wished they had stuck with SpongeBob. Sometimes, after all, innocence was a blessing.

“Yes,” she said. “And you should do the same, if you ever have a girlfriend or a boyfriend or anyone in your life who doesn’t treat you well. Okay?”

“Okay,” said Morgan.

“I mean it for real, Morgs. Seriously. That’s really important, okay? You have to take care of yourself. Promise me.”

“I promise,” said Morgan.