It sounds like your babies are claiming you, and your bed as their property. Growling at your son is like telling the other male in the pack to remember his place. When you are not there, he doesn't need to show your son he is higher than him in your affection. I would make your son take over a few tasks for awhile, such as feeding, and walking the pup, until he realises all the humans in this family are alpha to him. Snapping is never accepted as it will definetly get worse. I think your new guy is just trying to see where he fits in the big picture. Time and patience will sort this out; but he must never be allowed to snap or growl !
