Why does he always flirt and make sexual innuendoes?

Most likely because he luvs u or he's just trying 2 b funny. You gotta think of somethings in the past that happened between u 2 also. Other than that...I really dnt no. Unless he's actually being mean, then he's just probably a jerk. Somethings 2 think about are has he ever liked you? Have you ever liked him? Is he ur best friend or enemy?