Not that overwhelmingly.
Women do have mindless hookup sex.
But generally with a sure bet.
Attached women who have relationship free sex generally know other women who also do. They share someone discrete, capable, clean, witty, and usually younger and with endurance.
Often that will be a paid relationship.
It’s not going to be someone who might know people the women know. And they aren’t going to meet at bars or hotels.
Prostitution is a separate issue from married women who have affairs.
I expect that most of the women signed up for "Ashley Madison" are busy prostitutes.