So hiiragi isn't really in love or if anything doesn't really see himself in a relationship with shizu at all. Honestly, shizu snapping at all of them is so refreshing cause this Yuki part is sooooooooooooo frustrating.
I take their awkwardness at the end because they have been hit by reality. both must be wondering where their relationship is going and if it's serious enough for a furuture that involves kids. That's why even if the marriage remark was meant to be like a joke, taehwan didn't laugh.
I like how this uploader posts sweet stories! Thank you