When two idols date, they always have to do it in secret. Especially when one is from one of the most famous boy groups today, and the other is from a rookie group, still waiting for their time under the spotlight. 

They can't go out together. Even just talking and exchanging smiles would be too much to do in public. Too afraid to cause suspicion. Too afraid of what people would say.

It's this suffocating setting that causes them to have to sneak out, just to meet each other.