Maybe she figures she will outlive him and get everything.

I agree with your husband. Most women know. Not only do they know if it's happening, they know if it's *likely* to happen. I also believe most men will cheat if given the opportunity. I'd say approximately 80-90% of men have the propensity to cheat. Women lie to themselves for all kinds of reasons and it's so sad. I think in some instances women aren't even lying to themselves and they just accept it, not due to a lack of self respect, but maybe they've learned the art of detachment. There's a lot more to love than the physical... I mean, in the bigger picture. So maybe sometimes it's a silent, unconscious agreement between two souls they are okay with an open relationship.

I personally don't feel comfortable sharing, but I can understand it.

Knowing... that many men (and women) feel passing attraction to ramdom others, that muddies the water, for "knowing" one's partner is cheating.

Many couples go through difficult times, during which the body language signifying closeness, would say, "not in sych". Only each person can know, if they persist in their commitment, through challenging passages, in their partnership. ::my opinion + experience::

While I'm not a woman, I am a gay man. Firstly, I don't know why any man would be dumb enough to cheat on someone with large amounts of virgo or even scorpio in their charts. My best friend is a scorpio, SHE IS CRAZY.  I fear for any man who deciedes to make such a dumb act. Virgos analyze everything, so they will notice even the slightest changes in behavior, both signs can and will plot his demise. I usually let guys know up front that they can't play games on me. I always figure them out. Not because I am overly analytical, or paranoid, but because I have venus in pisces in my seventh and jupiter in pisces in my eighth, which gives me a sort of psychic sense of peoples behaviors and motivations. I know how people work, and I usually just get a "feeling" when someone is hiding something from me, which causes me to investigate. Being dominant fire and water, I give unlimited chances, but there will come a time when my patience will run out and he will be removed from my life. Almost like I never existed. I am glad that I have these placements because they really help me see into the human psyche and condition, which helps me understand why people do the things that they do. It also protect me, and allows me to see through the bullshit of others. Quite convenient really.  

I don't think it's a gender thing. I think you just feel that, especially if you're together for a long time.

I remember  when my friend's sister cheated on her long-time boyfriend.

She called him on the phone, they didn't talk about that, but he just asked her, all of a sudden "What's wrong? Did you cheat on me?"

The guy was a Scorpio.

I always know.  And I'm always shocked and saddened and very, very hurt by it.  My friends say I haven't gotten over the last time it happened, 4 years ago.  Haven't had sex since then.  I just... it broke me.  Somehow, I just couldn't ever pick the ones who didn't need to cheat.  And yeah, they got plenty from me.... but they were just what the song calls them:  "Walkaway Joe".