My W is only 34 but I think she is going through an MLC. She is going out a lot with younger people from her job. I know that she has been talking to an old friend from school and he is also going through a D. I don't know how far things have gone between them and I'm not going to pry and find out.
BA,
Between this and going back on the pill, plus a few other things your wife has said to you, this certainly has all the warning signs of there being somebody else. The GOOD news in that, is that it would explain a lot, and should she end whatever the heck it is, there's a great chance she'll make a move back towards her marriage.
What do you think she's getting from this other guy, that she's not getting from you? What have been her prior (not during this recent period) marital complaints?