Eric Thompson worked as a metallurgical engineer for North American Stainless from 1997 to 2002. He was fired three weeks after his bosses learned that Thompson’s then-fiancee (now wife) Miriam Regalado had filed a gender-discrimination suit against her employer, also North American Stainless. In those intervening weeks, Thompson neither kvetched, nor complained, nor bellyached about his fiancee’s mistreatment. Which is why the appeals courts threw out his lawsuit claiming that he had been terminated in retaliation for Regalado’s complaint.

Section 704(a) of Title VII prohibits an employer from retaliating against an employee because he or she “has made a charge, testified, assisted, or participated in any manner in an investigation, proceeding, or hearing under this subchapter.” Thompson did none of those things. The EEOC still found reasonable cause to believe his retaliation charge was well-founded. But when the 6th Circuit Court of Appeals assessed Thompson’s retaliation claim, it determined, by a 9-6 margin, that the law “does not permit a retaliation claim by a plaintiff who did not himself engage in protected activity.” Three other appeals courts agree with this position, although the EEOC does not.

Thompson’s so-called third-party retaliation claim thus turns on the thorny practical question of how many degrees of separation are permissible between the person who is claiming discrimination and the person who is claiming retaliation. Oral argument at the court is rapidly awash in hypotheticals probing relationships, which might be classed as fifth-degree retaliation (i.e., the complainant’s barber loses haircutting income) and seventh-degree retaliation (i.e., the complainant’s bowling alley loses bowling fees).

The statute is clear enough: You can’t be fired for filing a gender-discrimination claim. There would be no point in having Title VII if you could. Subsequent case law, including a 2009 Supreme Court decision, has further clarified that you can’t be fired for, say, offering factual information that supports someone else’s claim that your boss discriminated. So the question for the high court today goes to the next degree of retaliation: whether there is any legal remedy under Title VII when the fiance of the woman claiming sex discrimination says and does nothing to support her but alleges that he was fired just to get back at her.

Oral argument begins with a little exchange of family news between Justices Antonin Scalia, Ruth Bader Ginsburg, and Thompson’s lawyer, Eric Schnapper. Scalia wonders, “Is Ms. Regalado still engaged to this fellow?” and Ginsburg hisses “They’re married.” Schnapper politely adds that they now “have a lovely 2-year-old daughter.”

Scalia replies, “Oh, good. Well, why didn’t she bring this suit?” Schnapper replies that the wife would likely not have had standing to win her husband’s back pay or reinstate his job. Justice Anthony Kennedy wonders if shareholders can file a retaliation suit if the employer fires a very valuable worker and the value of the company decreases. (Let’s call that 11th-degree retaliation). Schnapper replies that this is different, “They singled out Ms. Regalado and Ms. Regalado’s fiancee. They didn’t go fire anybody else’s fiancee,” Thompson, he explains, “was the very target of the illegal act.”

This seems a clear enough distinction but nobody wants to make this one easy. So Justice Samuel Alito introduces the concept of three-and-a-half degrees of retaliation: “Suppose Thompson were not Regalado’s fiance at the time. Suppose they were just good friends.” When Schnapper equivocates, Alito pushes into fourth degree, “Does it include somebody who just has lunch in the cafeteria every day with the person who engaged in the protected conduct? Somebody who once dated the person who engaged in the protected conduct?”

Leondra Kruger has 10 minutes to represent the solicitor general’s office, which sides with Thompson in this case (for which reason Elena Kagan has recused herself from hearing this appeal). Alito asks her if, from now on, employers seeking to fire someone must “survey everybody and see whether this person who we’re thinking of taking adverse employment action against has a, quote, unquote, close relationship with any of those people?” Kruger replies that the opposite is true: “If the employer doesn’t know about the relationship, any allegation like the allegation we have in this case simply isn’t going to be plausible.”

Chief Justice John Roberts is also struggling with where to draw this line between friends, friends with benefits, and friends with standing. “How are we supposed to tell, or how is an employer supposed to tell, whether somebody is close enough or not?” And Justice Sonia Sotomayor wonders if it’s retaliation if the employer fires someone who just tells the complainant—in private, mind you—” ‘I know you’ve been treated unfairly. I like you; I like you working here.’ Would that person be close enough?” Scalia, rejecting all this goofy nuance, posits a simpler rule: “Why can’t we say members of family and fiances? Would that be a nice rule?”

“Well, I think that it would be an arbitrary rule,” Kruger replies. Scalia grins back: “I know.”

Leigh Gross Latherow represents North American Stainless, and she immediately accepts that Regalado could have sued and recovered on behalf of Thompson. Sotomayor starts to ask if she is seriously willing to commit her client to that position but then says, “I won’t do that to you.”

Scalia observes that if North American Stainless concedes that Regalado could have sued on Thompson’s behalf, the employer still has no idea “who he has to treat with kid gloves.” Latherow comes back at him with a hypothetical where there is retaliation but no one eligible to sue: “For example, if an employer announced a proposition that it was going to fire an employee at random whenever someone filed an EEOC charge, I might not file a charge because I wouldn’t want someone, even someone who I didn’t know, to be terminated …” Scalia will later describe this as the “World War II Nazi scenario.”

But Latherow follows with yet another other-worldly hypothetical, wherein, this time, the spouse of the North American Stainless employee doesn’t work for the company, but instead runs “an animal shelter in Carrolton, Ky. … but his only source of revenue was a generous gift from North American Stainless.” And she goes on to explain that in retaliation the company withholds its big Christmas gift. Or some such. Even Roberts looks pole-axed by what appears to be counsel offering up an example of 16th-degree retaliation.

Justice Stephen Breyer, unaccustomed to being out-weirded by his oral advocates and their elaborately complex hypotheticals, amplifies on this scenario to ask whether retaliation can similarly be claimed by “the barber who doesn’t get the haircut anymore because the person fired doesn’t have any money or the landlord who can’t get his rent?” He works his way from here on to the aggrieved proprietor of the local bowling alley before proposing a new rule: “hurting Mrs. Smith—the child, the wife, even the co-worker,” if they were fired merely to hurt someone, they all can claim retaliation.

Latherow politely replies: “Your Honor, respectfully, there’s no basis in the statute to adopt that rule.” At which point Breyer cheerfully replies, “And that is the problem with my theory.”

And that’s when the laughing goes from snickers to guffaws.

Oddly enough, in this case, Breyer’s theory seems also to be Scalia’s theory, which is (conveniently) also the EEOC’s theory, and might also be everyone else’s theory, too: They just shouldn’t be allowed to fire your fiance when you claim gender discrimination. But how to find that in this statute, without also inviting in a gaggle of aggrieved shareholders, landlords, barbers, and—inevitably—competitive bowlers. Ah, well there’s the tricky part. I can count at least four votes to draw the line somewhere before the barber. But I’m not sure I can count even one vote who might coherently explain why.

Like Slate on Facebook. Follow us on Twitter.