"Sure, honey, take all the photos you want. And if your girlfriend wants to see the birth of our daughter, she's welcome too!"

Washington Post advice columnist Carolyn Hax, as I have noted before, has an almost pitch-perfect ethical sense, and negotiates difficult relationship dilemmas with consistent skill and wisdom. She is too nice sometimes, however, and her recent advice to an expectant mother is a striking example.

The woman wrote Hax about how to handle the request of her AWOL husband, who left her mid-pregnancy to move in with his mistress, to witness the birth of his daughter. He also wants his family to be present. The mother-to-be said that she fully intends to allow her child to have a good relationship with her father, but she does not want either her weasel husband or his family, which hid his affair from her, around when the baby comes. “I don’t want any of them there,” Expectant Mom writes. “Many of them knew about the girlfriend but kept it from me, and I don’t want my husband to have the satisfaction of comforting me when I’m in pain. Do I have the right to tell them this, in some collected, nonconfrontational way?”

Hax confirms that she has that right, of course. “If he thinks that’s unfair, then he shouldn’t have cheated and left. And if his family doesn’t like your decision, then they can talk to your husband about it,” she says. Hax loses me, however by insisting that the only ethical justification for not allowing the betraying father in the delivery room is that stress “is bad for labor.” If your decision is punitive and based on anger, Hax counsels, “then please reconsider your choice.”

Here Hax jumps the ethical rails. Expectant Mom made it quite clear why she doesn’t want her husband at the birth: he left her, and she believes that he forfeited his right to be there by his actions. Of course she’s angry, and should be. Hax wants the mother to adopt a convenient fiction—she doesn’t want him there to avoid stress during childbirth—to render ethical a decision Hax believes is based on an unethical motive—punishment. In short, Hax is proposing self-deception and rationalization as a cover for retribution.

There are two ethical problems with this. First, it is dishonest, a lesson in devising phony motivations to disguise conduct. More importantly, however, Hax is just wrong: punitive conduct isn’t always unethical, and sometimes retribution is justice. I cannot imagine a better example. The mother had pledged not to let her appropriate anger harm her daughter’s relationship with her father, but her daughter isn’t going to know who is in the delivery room. The husband, as Hax herself acknowledges, forfeited his right to be at the birth with his adultery and abandonment; there is absolutely nothing unethical or unfair about his mistreated wife being the agent of his just desserts, and getting some satisfaction out of it.

I don’t even think the saintly attitude suggested by Hax as right is right. Let’s say that the mother believes that she wouldn’t find the presence of the husband stressful…just galling.  Hax apparently believes that in that case she should “reconsider her choice,”  and let him witness the birth. That, however, would mean that the husband has had his cake and gotten to eat it too; that he has had to suffer no consequences of his despicable conduct. This fails Kant’s principle of universality spectacularly: would anyone propose this as the appropriate fate of cheating husbands with pregnant wives, the general rule in such situations? Yes, cheating fathers: as long as your presence won’t cause health issues  for the mother or compromise the birth, you have a right to be

This is a case in which retribution and pay-back are the most ethical conduct, and clearly what the wife wants. Hax shouldn’t try to sanitize it.

She should applaud it.