Stay way from him. He is the kind of a man who would betray anyone in his interest.
 hanger-on someone who would betray anyone in his interest指一個人巴結重要的人以得到利益. 指一個人哪裡對他有利他就往哪裡靠, 白話的翻出即可.
What have you learned from your friend's drunkn car accident?