I obviously noticed Harry's shift in attitude towards Thomas right away. It was, of course, clear as day to a being of my skills.
It took a few days to figure out the reason behind the change, which I staunchly maintain is because I was just a puppy. And it certainly didn't take them practically spelling it out for me. I definitely figured it out before they literally called each other 'brothers' out loud.
I absolutely did not need to hear it a couple times before I really understood. Not at all.
That's my story and I'm sticking to it.