Teen relationship

Okay so there is this guy that told me that he liked me. I like him back. Well he told me he did not like my best friend like that but yet he goes to her and tells her that he does not like me but likes her. At school all he does is flirt with me. When he is around his friends he denies liking me but told my cousin that he likes me. I don't know what to do. Thinking about talking to him on Monday. I need help. Would not mind dating him but he is sending weird messages.