rich - Yep. S6 was placed right in the middle of the A.
Well said Si and Sci. SciDad is correct in stating that affairs are symptoms of dysfunction. Each person in the marriage contributed to it and has a part to play in the recovery.
That being said, what does busting the A gain you? Does it move your sitch forward to success? Is it a cheeseless tunnel at this point? Is it best to do nothing and focus on yourself?
In some cases it's the opportunity to lay down a firm boundary - "I will not live in an open marriage, and if you continue with your affair, then X will happen. Otherwise, if you end the A and come home, you will find that I am more than willing to work on any and all problems, including my own." I remember saying similar to that. In other cases, it may gain you nothing or make the situation worse.
The path you take is up to you, but I wouldn't choose without a clear head and from a place not based in emotion.
M: 8.5 T:10 Me:37 W:34 S:6
Retrouvaille and W moves back- 7/31/15 Piecing - 7/4/15 to present