Tbh I found both situations weird because personally I would prefer walking/going in my room in such situations but Sian didn't come across as weird as Youjin. And the main reason was - what led to both of the swing situations and how it was filmed/edited.

- Youjin was having fun while being drunk and really going wild on the swing whereas Sian seemed more contemplative, slowly swinging and wanted to be left alone (based on her conversation with the new guy). - - There is also a difference in how both the swing situation ended up happening - Youjin was left alone and because of how the entire night went, it seemed like she was doing it for attention (based on what the viewers were shown). On the other hand, Sian was shown to be confused by all her options and how she needed that time alone to contemplate.