(GUYS, PLEASE ADVICE!) Is he INTERESTED or just being FRIENDLY?

He is studying overseas. He calls me frequently when he is busy or stressed up (such as exam period). He would also give advices and encouragement whenever he knows i need it. However shortly after we start talking, he would say that he wants to resume his work or go to sleep.


There are times when he would teach Biology before my exams. He makes sure he teaches me till i understand though he has to be late for classes because of that.


When we skype, he would usually stare at me and look away and smile shyly when i notice it.


Sometimes he would use some endearment and also say ';bye bye beautiful'; when he's about to sign off.


On the other hand, he told his mum that he's not interested in anyone of my age because we are too young for him.


He said he can't wait to go out with me when he comes back.


He also talked to me about our graduation and told me his plans for his future.(GUYS, PLEASE ADVICE!) Is he INTERESTED or just being FRIENDLY?
this is some possibilities


1) he likes you or


2)he love you or


3) he is putting you as backup or


4)he is trying with other girls but he cant forget you.(GUYS, PLEASE ADVICE!) Is he INTERESTED or just being FRIENDLY?
How old is he?