@Athedite nah, if I speed read it like usual, I would've miss it too (and your comment made me re-read it to organize my thought about this one 😂)
and to be honest, I'm not sure my comprehension of the situation is the right one so I guess it's for the reader to interpret 🙃
edit: re-re-reading it, I can find another 2 or 3 explanations so yeah, just find the one you prefer 😁
tsundere could have been pouting because she wanted to play solo but ara-ara fufufu was already doing it.
ara-ara fufufu understood the tsundere and choosed to stop playing to get quality time together.
Tsundere is sorry for being cold before and thanks for the fluffy time that she just found out she was missing it.