He will know you like him and if he's interested, let him pursue you.
Honestly, it depends on the boy.
But a key confession pointer is to ALWAYS tell him when he's alone.
Wait, better warning *make sure he's alone before you tell him, use your friends to distract his or something. Because, if his friends hate you, you're screwed.
Tell him you want his penis. That won't freak him out.
boys don't freak out its usually girls who freak out LOL kidding...:D