[The reaction gets a laugh out of Rin, particularly when the popcorn hits right on Rei's glasses-- and it's mildly surprising that he's not throwing a tantrum about any butter and salt smeared across the lenses. Maybe he's growing up.]

Yeah? I always have a reason, you know.

[Standing in the living room with a bowl of popcorn in his arms, it looks like Rin has the upper hand in this unspoken war, and it's an advantage he's going to make very good use for.]

For one, it's fun. [He flicks another kernel at Rei.] Two, you look really cute when you do that cross-eyed thing. [Flick.] Three and more importantly, I feel like it.

[And another flick. Come on, Rei, indulge him for a minute, set your inner child free. It's not going to hurt.]