You are both cheaters so there isn't anyone in your marriage with any form of respect, trust or love for the other to base reconciliation on. Just two people living together who have proven they aren't worthy of being trusted.

Then there is your AP. Someone who readily slept with a married woman, what a prize. I can see why you are pining for him. I am sure your time together has shown you he is someone who could be faithful in a loving committed relationship.

You don't love your husband anymore, if you did you wouldn't have cheated om him knowing how bad his cheating hurt you. Or maybe his cheating didn't hurt you. It only made you mad he chose to be with someone else over you. Regardless, you showed you were out of the marriage the second you cheated on him as well.

File for divorce so you can both get away from the other and hopefully you will both end up with someone you can love and trust and hopefully you can both change enough to make yourselves worthy of someone else's love and trust. Staying in your marriage because it is safe while you are looking for someone else really doesn't say a lot about a person's character. Since you are too cowardly to divorce him, at least dig down and find a shred of dignity and self-respect and tell him about your cheating so he can divorce you.

Right now, neither of you are worth the love and trust from anyone.