Is my Wife Cheating?

[Steady on course]

Update:

Went home last night and informed wife that OM things needed to go. I did not memorize the entire script as puppy suggested, but was pretty close. When I arrived home, wife was very nice and snuggly. She had already ordered my favorite meal from our local restaurant and was unusually pleasant. I almost retreated from my planned mission, but gathered the courage and said " I need to talk to you about something.." As she was telling me about what she had ordered, appetizers ect.. I calmly located the two dollar T-shirt and coffee cup were it still sat on the bathroom counter, placed them in a small plastic bag and handed them to her. Silence for about 30 long seconds while I looked directly into her eyes and said" You need to remove these, and any other items from OM from my house right now. She immediately became combative and said, "who do you think you are? This is my house too. Who are you to tell me what to do." I said "I'm not telling you what to do, I'm giving you a choice to remove all things from OM, or I will do it for you." She reiterated the above again in a combative tone, and I told informed that "this is my house", I held up my hands and said I built this house with these two hands for you and our family, my blood is literally part of this house, and that what you did was incredibly disrespectful. If you want two hang on to OM things, and argue over it, I'll gather up your things as well. I'm not leaving this house over what you have done, if anybody leaves, it will be you." I turned and left, went into the game room with the kids for about 20-30 minutes, before I saw her out of the window placing them in the outside garbage can. I went back to our bedroom and said, Thanks for ordering a nice meal, let’s go pick it up. She was very solemn with a long face, and said that she did not feel like it now, and began crying. I said O.K., I'll take a couple of the boys and go get it. I took my two youngest boys, picked up the meal and returned in about a half hour. She was in the kitchen with the other boy's, obviously had a good cry, and surprisingly seemed pleasant. We all sat down as family and ate, with her at my side and actually engaged in normal light hearted and humorous family discussion.
After cleaning up, and getting the younger kids ready for bed, I asked her if she wanted to walk the dogs with me. "yes, I would like that" she said. It was a Cold and Rainy Midwestern night last night. We walked and talked about an hour and a half, despite the cold rainy weather. She told me that she was sorry for all of this, that she got caught up emotionally with other man because he reminded her of how I used to be...that she had been sad for such a long time, over a lot of things contributing to the distance between us, and she had told me this, but I ignored it. She said that A with other man was emotional and headed for a full blown no-holds bar affair, if circumstances had not have stopped it. I listened without interrupting for about an hour. She said that the night at the bed and breakfast they did meet, but at a party of OM clients were she did not know anyone. she stayed an hour, and left to the bed and breakfast. She said OM 19 year old son was with him, and I could verify it. She did not tell me because I would get the wrong Idea. You think? She said she did become attached, and did actually pursue him, before OM wife put a stop to it. Then went on to explain the secret phone, because OM would no longer take calls from her recognized phone either because of OM wife, or because he wanted to end it. She cried a lot, and said that she should have left me before looking for comfort from OM, but felt trapped. I told her that I loved her and did not want to lose her. I would work and listen, to make our marriage better. But, at the same time...I'm still dealing with all of this new information. I told her that complete transparency, and honesty from this moment forward. I told her I would not throw this back in her face at the next argument unless I found something more out that she has not told me. I need to know everything now, so I don’t find out about it later. This is the one and only amnesty night. There won’t be another.
This is where I am now.