Also really sells that they're a couple now, which is just delightful.
Sexy Times are great and all, but will make any relationship feel rather one-note. Them having these loving moments between them expands it all, and I think provides further weight to the fact that Suuna really does like Ruka and Ruka really does like Suuna beyond just the physicality - putting to rest any worries they might have had (well, Suuna, anyway).