Does he look like he is spreading out and trying to pancake? One of my boys does this, but with him it means that he is relaxing, as it is the same position he sleeps in!
He wheeks at my mum when she talks to him.
If you piggy freezes when you pick him up and squirms when you go to put him down it is more likely to be fear. But using my own experience I would say he may be relaxing xx>>>