Hmm. Trying to work out how to phrase this one. Talking about life generally… have you ever fell in love? I’m going to write this assuming you have, but if you haven’t (or don’t) I’d appreciate it if you went with me.
Did you give consent to fall in love?
Flip it around to the other person.
Did they, by conscious action, force you to fall in love with them?
I’d say the answer to both is “no”.
The question of free will is an interesting one Re: Love. In regards to the feelings, I don’t think we have it. The actions connected to it, sure, but not the feelings itself.
Whether Teddy was created by Billy’s subconscious or whether he actually fell in love the normal way (stating the obvious: one is a metaphor for the other in YA), he can’t choose to not be in love. However, he can choose how he acts. Teddy has already shown he has as much free will as anyone else when he left Billy.
Maybe his love for Billy would have withered. Maybe it would have stayed the same forever. But that’s the same as the rest of us too.