My friend has sex addiction, but he don't go behind females ( girlfriends, pros etc.) , he is married and have good sex with wife but again feel hungry and look for sex sites on internet , he always thinks about sex. How he can get rid of this addiction ?

Are you saying he does not hide cheating from girlfriends but wants to or does cheat on his wife?
There are sex addict places like alcoholics anonymous except they are for sex addicts.