Obviously there is some history here that you and some ABers are aware of. This doesn�t explain or excuse the answers above mind. I can�t say I have read anything of yours before.
You have to talk this through with your wife. If you don't clear the air, she will always wonder if you are being unfaithful - and the suspicions will eat away at your relationship. Recent �out of the blue� actions are a worrying sign, or any previous avarice. It may be that your relationship is at a very low ebb generally. Is it possible that your wife is having an affair and is using your indiscretions to deflect her guilt?
Don't confront her about it. Try to talk things through calmly. After all, your relationship was strong once - and may well still be. Give her the benefit of the doubt until proved otherwise.
Next time you spend time alone, open the conversation again, be honest - then have a heart to heart. Be honest with her, and ask her to be honest with you. You may not like what you hear, but at least you will know what's really going on.