David is a professional jerkass who loves their friends a lot but is an asshole to them most of the time, even if it is in a playfuly way.
That's the most accurate description you need about him.
Oh and,
He is actually very friendly so don't be afraid to talk to him, he'll most likely open himself to you after a while. Also talk to him about Supernatural and you'll have his love forever. Also Doctor Who, Sherlock BBC, Teen Wolf, the Avengers, SUITS, Arrow, the Walking Dead or anything like that and he'll jump on you and never let go.
Or just let him know you like rock/punk/punk-rock/heavy metal or any kind of music related to these.

Although it says winter coat, this design has been most likely settled as main one.