He keeps coming to me for comfort. is it normal?

A guy I'm close friends with keeps coming to me for comfort. He's in a relationship and is engaged. They don't live together but they live 5 minutes away. He doesn't always come to me, 20% of the time he goes to his girlfriend but when he's feeling down he'll call me up and ask if he can come over. No sex, no intimacy at all strictly him sitting with me and telling me what's on his mind about everything. He also came to me first when he lost his job, came to me when he had a fight with his brother and comes to me as a refuge 80% of the time and her 20% of the time. He tells me he loves me and that he is grateful for me and how he doesn't feel as relaxed and doesn't feel he can be himself unless he's with me. He said to me he doesn't laugh with his girlfriend almost at all and he's always laughing with me.

I don't have a desire to date him but is it normal he does this despite being engaged?