You can surely know that your pet is happy to be with and like you if there are no signs of provocation, just love. If he does not bite you, hump his head, puff his beard up when you get near, or sniff at you, it is good.
There are some easy signs they will show if they are happy with you:
They close their eyes when you hold them
Lay flat and look relax
Climb on your side, let you handle them
Lick your hand