You haven't seen Suna smile, at all, he's never been the type to smile openly or just regularly. You were bored and wanted to make him smile, so you suggested some stuff he likes, yet he didn't smile at all. Inviting him over to your house? Didn't work. You suggested to him to trade a smile for a smile as you had a slight smirk.

"I'm not going to." Suna replied with a deadpan face.