Caregiver Confessions: The Dilemma of Unconditional Support

So I'm in grad school for psychology and have been the primary caregiver for my uncle ever since his wife passed away last year. We're only about five years apart, but he's had a lot of health issues lately, which is why he moved back home with me. It's mostly manageable, except for one thing that's become this weird grey area. There are times when I find myself disciplining him in ways that would be completely inappropriate if I was his real caregiver, let alone his niece, and the funny part is, it kind of works! He'll do something dumb like leave the stove on or forget to take his meds and then he'll act all remorseful and say things like 'Sorry Auntie...I didn't mean to make you worry.' It's not that I'm a strict person by nature; actually, I tend to be quite lenient. But with him, it's like having some weird control issue over these little adult mistakes of his. Here's the kicker: we've never talked about this dynamic and I don't know how to even bring up the subject without sounding completely insane. Is it just me trying too hard as a caregiver? Or am I actually getting something out of this twisted pseudo-parental roleplay that I'm not admitting? It's like, on one hand, I genuinely care for him deeply; on the other, there are days where I catch myself being unnecessarily strict with him over petty things. He doesn't even seem to mind when he gets 'punished', though it’s just me reminding him of the rules or grounding him from video games for a week. I feel like an asshole talking about this but seriously...what gives? Is there something messed up here that I’m missing?