Is my rabbit sulking

I have a buck called Malcolm and he has been totally attached to me - and I mean totally. He jumps up on me when I come home from work and 'gives me a kiss'. He follows me everywhere, and when I am sitting down he is constantly jumping all over me. In his quieter moments he sits on my shoulder and licks my ear - or rather, he used to.
We went on holiday last week and left him with friends. It's like we picked up a different rabbit when we came home. Malcolm will not bother with me at all!
A few people have suggested that he's sulking because we went away and left him. Anyone agree? Anyone experienced similar? Has anyone any other ideas?

Rabbits can most definitely sulk.

It sounds like you need to do some serious sucking up to him to win him back.

There is the remote chance that he is unwell, so it would be worth checking him over and looking for any signs of ill health or being uncomfortable, just in case his beahviour is not due to a sulk.