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This sounds like a very complicated situation and I can understand why you are concerned. Typically psychologists limit their relationships with patients to office visits only and this is consistent with the ethical and legal guidelines under which we practice. It sounds however that your wife works with this psychologist which would change their relationship from doctor/patient to co-workers, which would alter the rules under which they can relate.
In short, if your wife is paying this man to be her therapist, it is not appropriate for them to be exchanging multiple cell phone calls and expressing sexual interest in one another. If this is the case, you would have grounds to file a complaint with the board of psychologists in your state. They would then launch an investigation into the matter.
If your wife and this psychologist are co-workers, you would have no grounds for such a complaint.
Either way, I would strongly suggest that you and your wife talk about this issue and perhaps seek marital counseling to work on whatever issues are happening between the two of you so that you can feel more trusting of her.
I'm glad that you are on the track to working things out. Please don't hesitate to contact me with further questions should anything else come up.
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