I truly believe the excitement an A creates is one of the #1 reasons they do it. I recently had the "opportunity" to participate in an EA (one of h's friends). I chose not to for obvious reasons, but it was tempting and I'm just being honest. The excitement, the forbiddenness, the fact that someone else found me attractive and was showing me attention, etc. It's all wrapped up w/ a huge red bow. Also, as we all know, the honeymoon phase ended a LONG time ago in our M's. There are some ways to spice things up, but there will never be that initial excitement, stomach flutter of a new romance. That is what is enticing, IMHO.
If your W is coming back to you, it's because she has finally "figured it out." You obviously will have a lot of emotions to deal w/ and it's not easy, but in the end it will be worth it.
Me: 38 H: 35 S4, S5, S10 Bomb 01/07 Wanted D - nothing would change his mind Numerous A's prior to D bomb; EA prior/during D bomb Piecing 04/07 Deployed for a year 05/07 Still Piecing 2010 M 11 yrs 05/10