in law called to say my wife has QUITE a sexual reputation

Before we got married my wife showed signs of not being faithful, but I could not absolutely prove it. When two of her brothers asked me if I actually realized what I was getting into by marrying her I assumed they referred to her controlling behavior bossiness, moodiness and etc. My wife got a call from an old lover at my parents-in-law house that she took out of the room, this was not the first one from him while I was there. A few years ago I got a call from a sister-in-law that told me completely out of the blue that my wife had QUITE a reputation. Why would she do this after all these years?