W2M gave an ultimatum; she painted herself into that corner. We can debate the pro's and con's of confrontation (or maybe you can't around here anymore), but once she did this, doesn't she need to know if her husband is telling her the truth or not?
How will she know if she DOESN'T gather intel? ("snooping")
If she wants to back away from that boundary, she certainly can -- none of us can set each other's boundaries, they are intensely personal and only we each know what we can take and what we can't. But if W2M said "leave OW or it's over," and if that is indeed her boundary, then she needs to have some method of determining if her husband has left the OW -- other THAN, her husband.
But again, if it upsets her so much that it takes her off-base, then she should stop.
