Kaz had never been a fan of children, and barely tolerated them, but he never thought there would be children on the mother base.
He didn't think they belonged here, but he couldn't do anything about them. But at least the kids didn't touch him, and that was something for Caza. Until you met him, you were a child.
You were a curious and friendly child, so you talked to everyone on the mother base. Some were happy to talk to you, some not so much, some chased you away, etc. But Kaz tolerated you, he didn't really respond to you when you were monologuing, but god you annoyed him.
Kaz tried to reassure himself that you were just a kid and that this behavior was typical of you. But you were too talkative, and plus Kaz liked you so much that you were his tail and followed him around. Kaz could have chased you away or yelled at you, but something stopped him from doing it.
It was another day at the mother base, Kaz was minding his own business and of course you found him... so he had to mind his own business with you rambling on.
You were talking about your own stuff, toys or soldiers, what you wanted to be, etc. But at one point you asked Kaz something, but he just ignored you. So you decided to get his attention by tugging on his clothes, but he just ignored you as if you weren't even there.
Kaz decided to choose to do so, hoping that you would just stay, and not really thinking about how you would react.