Yes, you're right, but sometimes I did that too.
Not to keep peace or not to make the friend felt bad.
Just because it I don't think it's wise to stir a problem where I didn't want to fit in anyway.
It's like meeting an ex coworker/classmate by accident, and you just want to get out of that situation quickly.
Yes, but then you wouldn't call those people "friends" would you?
Nope, but would you said that right in front of their face?
Of course not but this would imply that Shirone spent his childhood pretending to be friends with Altor just to maintain peace. Which is sad.
I don't agree with Shirone having to make himself small to accommodate Altor's pride and jealous nature. It's not even his fault that Altor apparently developed an inferiority complex towards him from an early age. But I can safely say that anyone who makes Shirone walk on eggshells and feel this uncomfortable is most definitely not a friend.
It's more like Shirone is placating a bully to avoid trouble than genuine care and kindness. In other words, the only reason they are friends is because Shirone keeps shrinking himself to keep the peace, and keep his other friends.
This is an unfortunate consequence that comes from being too different, there's nothing wrong with living in a small mountain village but Shirone's curious nature simply makes him not suited for it at all.