When my wife has sex with married men, she likes to find out what they like that their wife won't do, like fucking her in the ass. Many of the wives also will not suck their husband's cock as much or as long as he likes. My wife will suck those guy's cocks often and for long periods of time.
My wife likes to be the fun-fuck for married men. Like your wife says, that is what a hotwife is good for. If a guy just wants plain vanilla sex, he could just fuck his own wife.