Ugghhh, have I mentioned this is hard?

[sandi2]

First of all, do NOT tell her about the receipt you found. She will twist it around so much she'll have you believing you're nuts for mistrusting her. You are already doubting yourself. You need to mistrust her. Yes, that's what I said! You cannot trust a wayward who flatly refuses transparency. The burden of proof is on the cheating spouse and she is doing nothing to even try to earn your trust again. That, alone, speaks volumes.

Another thing I'm debating is how I think she'll respond. If I demand transparency will it drive a wedge between us and create tension that will only validate her lack of feelings toward me? Would it be better to just keep DBing?

What do you mean by "just keep DBing"?

Let me say this about "demanding transparency". You don't have to demand it, that's up to you. However, if you have her told that it will take transparency for you to trust her, or to heal, or for the M to work....or whatever, then you need to do something if she is not cooperating. For her to continue on without being transparent and you to just sit back and do nothing, would be very bad. Any future respect for you as a man or her H would pretty much be destroyed.

Did you ever state a boundary in relationship to her continuing an A? Did you make the transparency a stipulation to staying in the M? If so, then without consequences, it's ineffective.