Big deal out of nothing?

It’s really dumb to post about but I did this prank on my grandfather. My brother and I used a Bluetooth speaker and played moaning sound in my grandfathers room and played it off as if we didn’t know what was going on. We succeeded in the prank! Yay.. but when we told my dad at first we used porn hub for the prank he started saying stuff like you watch too much porn. Blah blah blah it’s disgusting. then he said you know I can see your history even though you delete it STOP WATCHING PORN. I only watch that stuff when I’m bored! (Keep in mind my whole family was on the car too!) I was embarrassed and I felt horrible for watching porn! It’s nothing to be ashamed of right? And he definitely should of handled that differently is what I think. Any opinions on this?