What will you do if your inlove with your BESTFRIEND ?
If you are in love with your best friend, then you should let him/her know how you feel. They may also feel the same way about you, though you should keep an open mind so that you don't end up getting disappointed or ruining your friendship.
Well, I married him. But I was not a teen, but quite a bit older.
Talk to them about it and accept their answer and move on.