A little context before I begin: My father is a very nice guy in general, but he has always been extremely wary of his physical health, but no matter how many times he gets checked, there are no problems. He has been hot and cold about seeing a medical professional, always being scared of it but then criticizing doctors when they don't find any physical issues.

Moving on to my main point; my father checks his blood pressure nearly every day, and when he's not, he relies on my Apple Watch for that. I calmly tell him that it's not very accurate, as it is connected to MY data, but he insists that it works. When he initially tried it, he put it on completely wrong, and for anyone that owns an Apple Watch, you know there's usually a metal thing that fastens into the holes in the band, but my father STRETCHES the band so much to tighten it.

Last week, I wake up to my father knocking on my bedroom door, saying that my watch is "broken." As I was still a bit half-asleep, I ask him what he meant. He walks back to my room and I see my watch band basically ripped in half. Now, I don't really mind how much it cost, but this has been an issue where my father relies on "products" that would fix his health and then lose his temper when the products "don't work."

My mom decided to upgrade to a new Apple Watch and I got a band that wouldn't rip so easily, but now my father has been secretly wearing it and denies when I catch him putting it back. The Apple Watch is just a small part of how paranoid my father is about his health, as he is always checking his blood pressure but is EXTREMELY stubborn and loses his temper when my mother or I ask him to get some sort of mental treatment.

So, WIBTA if I told him off for this?

EDIT: I did tell my father before to get a watch of his own or let us get one for him, but he thinks it's too expensive and says we should save our money (even though he himself has spent money on numerous products that don't exactly improve health.