"We don't have to sleep."

It's not a proposition but it certainly sounds like one to Jyn's own ears and she decides, fuck it, and doesn't not clarify she really meant they could eat in his room and like read a book. She remembers the intensity in his eyes when she told him about her father, she maybe wouldn't mind some of that directed toward her pants situation.

(Maybe she should stop thinking of it as her "pants situation".)