Most people when they travel like to use their own stuff.
When I go to my in-laws or my parents, i take my own soap, cream, toothpaste, comb, so what if he did it.
I bet 90% of all bashing this scene have done exactly that.
I have seen people take these stuff even if they are staying at 5star hotels, I don't see why people are making a hoopla about this.
AC was a little bit much, but not that bad.
When I took my daughter to my in-laws place for the 1st time, small town with 12 hour electricity cut, we got a AC and generator both installed there but we did confirm with the olders 1st. And that is what Arnav should have done, asked Khushi's family.
People just need to stop criticism in every small things. This is a fictional story and writers are allowed to have some creative leverage.