Why does he want to make me jealous?

I am have been friends with this guy for the last 2 years (we met at work). He texts me a lot (every morning), and he always talks to me on the phone (gives me his true opinions) -- I have always been there for him through ups and downs. We have a lot deep conversations.

I don't know. But, he always calls me to come out. And when I get there he pays a lot of attention to other girls. Even though he called me to come there and hang out. He gets a lot of attention from girls because he is really nice, outgoing, funny, and has a great heart. I don't understand why he keeps bringing up other girls, posting pics of himself with other girls. Does he think this is a good way to get my attention? Do guys try to make the girl they like jealous? I always act normal, and in fact are always friendly to the other girls who are around me. Generally, it's not my nature to feel 'up-staged' or threatened by other girls. I consider myself who gets along with various types of people. I have a lot of confidence in myself. But, even still, I don't why he does this. Flaunts girls in front of my face. And then tells me he can't live without me, and I have to come out and be where he is. What the hell is that about? SUGGESTIONS?