Their feeding response (especially when young) is pretty amazing. They're programmed to eat as much as they can when it's available - some stay in feeding mode for quite some time after a meal. Chances are he's not actually hungry (as you and I think of hunger). As long as his meal was of appropriate size for him, you're good.
You certainly can feed multiple animals in one sitting as long as the total amount eaten is an appropriate amount for his size. Anything more than that and he'll probably end up just pooping more or not eating consistently for you.