There is much room for different lovestyles on the forum.
I cheated on my husband with my current boyfriend. The story is detailed in other threads.
But three years ago-I decided to get my head out of my ass.
I committed to full honesty and we began attempting to build a dynamic that included my boyfriend (he was already part of the family so just ending contact was never an option).
I can say with certainty-that would NEVER EVER EVER have worked if my boyfriend wasn't equally committed to righting the wrong he made with my husband. I made a wrong I was committed to righting. He made a wrong he was committed to righting.
Something that seems missing in your situation-and this is a common oversight-but VERY unhealthy;
Is MAKING AMENDS.
When someone does a wrong; they owe an apology AND making of amends.
To ask you to "try again" without those steps being made is ludicrous. It's asinine. It's unreasonable. It's unloving.
If your husband wants to put the past to rest in terms of the affair and ongoing drama this woman brought to your life-
he needs to understand that there are certain steps to making that happen.
1) he apologizes for his wrongs-fully acknowledging his responsibility
2) she apologizes for her wrongs-fully acknowledging her responsibility
3) he makes amends and attempts to repair all damages caused by his wrongs
4) she makes amends and attempts to repair all damages caused by her wrongs
5) he rebuilds trust with you
6) she rebuilds trust with you
Until THAT is done-there isn't any future chance at all. Period.
It's important to realize that there is a difference between having a trusting and respectful relationship as described by the above posters, where both partners talk openly and honestly with one another, prioritizing the relationship and working to the better good of all.
having a situation where someone has broken trust and needs to re-earn it.
When trust has been broken, agreements broken, boundaries over stepped-
FIRST YOU HAVE TO FIX THAT DAMAGE.
Only after you have cleaned up that mess and repaired that damage can you expect to return to having the full privileges that come with the trusting respectful relationship from prior.