Why do you think he's approaching you at all? Do you work with him a lot or is he more or less a stranger in another department? If he speaks to you that freely he probably feels he knows you well enough and you're equals. Do you think he knows you think it's dickish or is he just joking and bad at judging how he comes off?

I have one coworker who speaks like he's the worst heathen in the world but his actions are conscientious to his employer and his family. I usually expect the opposite which kept me from enjoying him as a friend for a while until I figured him out.