I like a boy his name is ***** I like him so much. But he is catering my best friend. They broke up five times. When they broke up I asked him out but he said no.

He said no to you, and he is interested in someone else. Look elsewhere for a date.

Why should I

Why should i
What else can you do? Drag him by the hair to your cave?

How many times does he get to tell you NO before you get he has no interest in dating you? Get another guy, this one is still busy with your friend.

He is dating your friend and he has already told you no once. Why would you ask again?
What about No! Do you not understand?

Why should i

If you really have to ask that then there is no help or advice we can give you.