One of my clmates behave badly with me ?

actually he makes fun of me when i am with other friends ,he trys humiliate me,but later when he is alone he will say sorry for misbehaving.He says he loves me but sometimes behaves very strangely as if he doesn't even know me.His behaviour shows he is even jealous when I am with other friends(boys) .I am totally confused , is he just trying only to flirt with me ?