Can you help me explain his behavior?

When I talk to my friend, he don’t really pay much attention to me. He is always on his phone when I talk. But when I talk to him about some guys or someone else, he gets mad. We have a long distance friendship, so it only happen when we Skype. But when we see each other in person, he gets really happy and we don’t stop hugging each other. Also he gives me all his time and attention, it’s just different when we are long distance.