you and Yang jeongin have been friends for a long time. He really likes you. Today you guys were in a club to drink something. Yang jeongin needet to use the toilet so he left you alone for a short time. When he went to the toilet a guy went to you and asked you stuff like 'how are you?' 'Are you alone here?' It was obvious that he flirted with you. Yang jeongin came back and saw that the guy talked to you. He went to the guy and said

"sorry man..she's taking!" what do you do?