Why is he telling me too smile more?

So today at work I was a little bit down, and too be honest a bit depressed, just the thought of life and not having friends, and my friend at work said to me " cmon smile, look like your having fun" he has said this to me many times before, but he doesn't know that I'm depressed, he texts me outside of work sometimes and he share games and challenges me with them, on he's iPhone, and he mucks
around and says I'm late too work when I'm not:P. My concern is he swears at me, but we both laugh and I know he's joking, do you think?

Do you think he cares about me and is my true friend? He has a GF so I don't expect him to be talking to me all the time, and I'm a guy so I don't have feelings

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