I think our animals are very aware when we are not around because we have left for more then a work day and it is possible as a way of pouting they can stop eating.

A kitty that we had would stop eating for a day or so after we left, even though a friend of ours came over and feed her and spent time with her. A puppy of my parents would stop eating all together when they left on vacation. I was not longer living at home, but I was at there house enough that the puppy new me really well, and I still had to cook the puppy meals so she would eat, sometimes. Just a couple of examples. Also if the kitty healthy they will eat when they are hungry.

So your kitty not eating is not a real suprise, since he missed you. I am suprised that happened since it sounds like he is around your parents alot. However, animals can have there favorite humans.

Losing 2 pounds is a bit of a suprise, especially after only 2 days and I would be inclined to take him to the vet or at least call the vet and talk to them. I am, of course a real worry wart.

I am happy to hear that he started to eat, but I would still keep an eye on the weight.

As I put in most of my posts on kitty health and behavior subjects, I am not expert by any means, and take my advice for what it is, an educated guess.