@zerio that kind of stuff has no general standard, it depend from people to people but i guesse if you're close enough to be seen as a couple by your parents, it should be a good start.
@quagzlor
The parable of the north wind and the sun describes how the north wind and the sun were competing on getting a traveler to remove his hood.
The north wind forcefully tried to remove the hood by blowing at the traveler, which was an attempt in futility as the traveler simply clutched his hood tighter.
The sun on the other hand made it a bit warmer, which persuaded the traveler to remove his hood.
The joke here is that like the guy, pulling off her clothes is an attempt in futility. But going into the kotatsu himself (while naked) he made it a bit too hot inside (if you know what i mean). I believe there was a bit of implied wordplay in there.
@zerio
There isnt a set standard. But a good starting point would be if she is close enough to go along with it and other things, it is alright. For example, this isnt the first time she has been naked in front of him. She even technically slept with (on) him naked.
@Walter_vi_Britannia Dude im not Morgz my name is MrOGZ, and i don’t have any connection to Morgz nor i watch or like him. This name just sounded cool when i first put it.