Please help me find a drama.

I'm not sure if it was chinese or Korean but I saw a reel of it.  The guy and the girl were talking about keeping something a secret in a room with a sliding glass and said we can't let a third person find out. Then they saw their friend outside who was looking for his phone and said we can't let a fourth person find out. But then another girl comes out saying they were helping look for the phone. 

 Chardd:

Do you have any other descriptors that might come to mind to help narrow it down?

Were they students in a school setting or plain dress adults in another random windowed area, etc?

I think they were plain adults. They were in a room and the girl was sitting down on the couch and the guy was standing. It looked like an apartment room or hotel room.I remember seeing the bed behind the couch. 

 Haitang:

Post it here. https://mydramalist.com/discussions/recommendation-forum/377-discussionsearch-find-that-drama-by-desc.-or-plot

Thank youuu