That's the thing children don't always take into account enough, but parents will. I think we got our first cat when I was about 9 or 10, & we lived in a flat. We were told that our parents would pay for the things it needed (food & so on), but us children were solely responsible for emptying & cleaning its tray, feeding it, brushing its fur if it needed it & keeping the sofas fur-free. My Dad in particular was adamant that if we didn't look after it, the cat would be gone & we'd never have another pet again. He wasn't the type to give in either, but some parents will say it's the child's responsibility & then end up doing it all themselves when the child gets distracted by school, socialising & wanting a boy/girlfriend. I'm glad the OP's dad is wary, as that means they're all having to think hard about the decision now instead of just getting one & then regretting it a couple of weeks down the line.