This is when Leafstar and Billystorm are talking out in the forest, and Billystorm mentions the fact that the daylight warriors will probably have to make a decision about their loyalty soon:

Leafstar found that her heart was suddenly beating faster. What if he decides to go back to his housefolk? "Which would you choose?" She whispered.
"It's so hard," Billystorm responded with a sigh. His amber gaze was fixed on a tiny beetle as it climbed up in a grass stem a mouse-length from his nose. "I love my household, and they're kind to me. I know they make my life much easier than it would be if I lived in the Clan all the time." He took a deep breath, swinging his head around so that his warm gaze fell on Leafstar. "But I could never leave you," he murmured.
Leafstar's heart beat faster still, and the forest blurred around her into a chaos of green and gold. "I would never want you to," she breathed.

ACWDJEJFEWIJK CUTENESS

From SkyClan's Destiny