@botodopo she’s not one, she’s a
gadget otaku
If something you’re obsessed about is offered to you on a silver plate, of course you’d do your best to grab it, right?
It’s told better in the LN how much of a Gadget-Nerd she is, but not so properly in the manga/anime perhaps
It was a good strategy attacking her weak point
He thinks of miyuki as a child because she behaves so, in front of him- she gets jealous, losses her cool, and can’t properly control her magic, as it gets influenced by her emotions.... I think it happens especially due to him though, every time she looses her temper, it’s bcoz of him, or someone mocking or being harsh to him etc.. plus, she tries to be adorable in front of him sometimes, he might think it’s childish (but that kinda only happens in front of him)