Although I do believe there are women who willfully entice married men, often the "mistress" has been mislead by the husband, believing that the marriage is already doomed. Some husbands even "court" an unwilling woman, playing on her emotions, insisting that she is not going to cause the divorce as the marriage is already doomed.
On the other hand, the marriage could already be a failure, and the wife blames the mistress for destroying her already dead marriage, thereby shifting what might have been her part of the blame for the divorce onto the shoulders of the mistress.
An affair is actually a symptom of an existing problem within the marriage, getting to the root of the problem could not only restore or save the marriage, but could also stop the husband's philandering, that is, if he is committed.
In my opinion, though, willfully enticing a married man away from an otherwise healthy marriage is unforgivable! But once again, the mistress did not make those marriage vows, he did! And he should honor them!
...just my 2c worth...