How do you know he sends nudes to the girls and have you seen them?
No seriously a little more info can help..
Perhaps simply put he tends to gage who he can send them too and who he can't, he's obviously confident or else he wouldn't do it to start with and he's giving you compliments so that also points to him being confident.
He may very well just see you as someone he gets along with or he maybe playing his cards differently for what reason ? Who knows, he could just be a player knowing how to do it, or he could think you're "ok" and is treading carefully, I think time will tell.