Ready.. Set... Question!!!

I've given him all of the right signs. i've left clues but i guess that he's slow. plus he's still close with his ex so idk who he likes... he's like reading a book that you can't understand sometimes.. plus he makes me feel like i am the only one that he likes then acts all rude then he acts kind then he acts like a jerk wad... idk wat 2 do? do i leave it and move or do i jump and ask him !!! Plus he totally has my back if someone tries to hurt me because he has proven it. He also has acted as if he was going to ask me out then he gets scared and walks away and says that he can't do it? what does that mean? Help!!!