There is a word to describe this.... inseparable.

And they are inseparable. These two spend their days together and their nights together. Axl gets upset when he is not next to his mom. He has a whole routine that he goes through just to be at her side. If my wife and I are sitting together on the loveseat watching television then Axl wants to lay down between us. And he always gets his way. Soon that gets to be too cramped so I usually go sit on the other couch and then he stretches out with his head on her lap. Axl has become so devoted to Jackie that when she leaves him alone by accident - like if she goes outside on the deck and he wasn't quick enough to follow her, he comes to me and makes very worried-sounding moans to get my attention, which makes me get up and let him be with her.