My guy friend (co-worker) always points out my flaws, this really makes me insecure...?

we usually joke around, but at least once per day he will make fun a physical characteristic that i have no control over (i never make fun of a persons physical characteristics--thats just wrong, not funny at all)..like my height. It really makes me insecure, especially because at times he will just stare at me which makes me think he staring at some other flaw...Im very blunt, but i dont like to make myself vulnerable either, i have hinted that it bothers me (i said, why do you always make fun of my height, it seems to bother you more than it bothers me--he didnt really say anything...but continues to make fun of it everyday). He really gets on my nerves these days, his jokes are gettin old--he just needs to grow up!