If he's your boyfriend how come he never calls you?
Some people go about relationships differently and don't always go by a rule to call their boyfriend or girlfriend, so that could be a reason. Another reason could be, though he is your boyfriend, he isn't as interested in you as you are with him so he doesn't feel it's as dire for him to call. It's best to sort it out with him, and find his reasons for his lack of calling.
He obviously is thinking about you when he calls you constantly,but it usually depends on the conversation,if its a flirty type hes into you,no doubt but if its how u and your friends usally talk hes a good friend,if he calls u over and over to be awkward he likes u but hes shy or hes a prankster or hes a stalker
The first thing that might come to your head is why he wants to stay .... like did you something? well the anwer can be that he is overwhelmed or that he needs some time to think about you and maybe hes in a rushed reltioship with you, you never know ..... are there any hints hes given you ? good luck :)