Considering how little we know about the situation what makes you think she was the seducer and not the employee? Seems somewhat sexist to think the woman is the one to blame.
Seems a bit more sexist to assume that if she was the "seducee", that she was somehow helpless to prevent herself from sleeping with the guy.
The known quantity is that she was married to the OP. It's her responsibility to not sleep with someone else or terminate the marriage if she decides that she wants to
