I completely understand your anxious and confused feelings as I read about your situation. Let me help clarify things a bit: In Korean workplace culture, it's quite common for seniors and juniors, or supervisors and subordinates, to build relationships by having coffee or meals together. There's often an atmosphere where interns or new employees find it difficult to decline such invitations from their seniors. However, "inviting someone to your home for a private dinner together" is likely more about building personal intimacy rather than typical workplace culture.