Serenity couldn't bring herself to refuse, and by the time she came to her senses, she was already lying in bed with Jackson.

She sighed and thought, 'So what if we're sleeping together? Whatever. It's not like we've never done this before.'

But lying in bed now, she couldn't fall asleep because he was beside her. So Serenity decided to bring up a topic. "Why do you still call me 'Sis'?"

"Don't you like it when I call you that?" he asked.

She hesitated for a moment. "It's not that I don't like it, it's just that... um, it feels a bit weird to be called that now that we're dating."

If someone who didn't know them heard him call her that, they would probably think she was his birth sister. But in a way, she had gotten used to the term because he had been calling her that from the beginning.

"What if I call you by name in front of others?" he asked. "And I'll call you 'Sis' when it's just the two of us."

"You... seem to really like calling me 'Sis'?" Serenity asked.

"Yeah," Jack