After they get together. At a bar hanging out with everyone and everyone starts teasing Seo Yul.
Seo Yul: *After they get back home* I want to do bad things to you.
Sung Ryong: Like what? *smirks*
Seo Yul: Break your legs.
Seo Yul: Push you off a building.
Seo Yul: Drown you into a river.
Sung Ryong: Kinky.
Seo Yul: ...
Seo Yul: I'm gonna fucking kill you! You piece of shi-