I'm in love with my best friend. I can't stop thinking about him.
I see nothing wrong here. Is it mutual?
I like him and he likes me back. My parents want me to choose someone better than him.
It's okay to be in love with your best friend. If the feelings are mutual, you should be encouraged to pursue your friend.
Not in this situation, my parents will never approve of him and he is a hobo.
It's not up to your parents to decide who you can or can't love. It's more than acceptable to love your friend.