Last week, 157 House Republicans voted against the Respect for Marriage Act, a bill that would repeal the federal ban on same-sex marriages. But only one of those no votes was “thrilled to attend and celebrate” his gay son’s wedding days later.

That dubious distinction goes to Rep. Glenn Thompson, who’s serving his sixth term representing a swath of western Pennsylvania. Thompson’s son confirmed to NBC News that he’d “married the love of [his] life” and that his “father was there.” (NBC News and other outlets are not naming the son or his partner, as they are not public figures.)

And Thompson wasn’t a passive attendee. BuzzFeed News reported on Tuesday that he delivered a speech at the wedding, praising his son’s choice in partner and welcoming him into the family. Thompson told his son’s new husband that he and his wife are “just really thankful that you’re here. It actually goes beyond that, as parents. We love it when they find their one true love, especially when they become a part of our families then.” To which I say: Wow, the chutzpah on this guy.

There’s no shortage of Republicans who have characterized their shift to approving same-sex marriage or LGBTQ rights in general as part of their support for a family member. Last year, when Rep. Liz Cheney, R-Wyo., said she’d been wrong to oppose gay rights in the past, she cited her sister, Mary, a lesbian. “I was wrong,” Cheney said. “I love my sister very much. I love her family very much.” Likewise, Sen. Rob Portman, R-Ohio, embraced same-sex marriage in 2013 out of support for his gay son.

Thompson has made no such political shift, despite he and his wife being “thrilled to attend and celebrate their son’s marriage on Friday night,” as his press secretary, Maddison Stone, told NBC News. Stone had previously told the Centre Daily Times in Pennsylvania that the Respect for Marriage Act is “nothing more than an election-year messaging stunt for Democrats in Congress who have failed to address historic inflation and out of control prices at gas pumps and grocery stores.”

That’s an interesting view to take given the precarious status his son’s marriage could be in given the supermajority conservatives have on the Supreme Court. Pennsylvania, like all states, has to accept same-sex marriages as a result of the 2015 Supreme Court case Obergefell vs. Hodges, which established a federal right to such marriages and invalidated state laws that said otherwise. Obergefell followed 2013’s United States v. Windsor, which held that the Defense of Marriage Act’s federal ban on recognizing same-sex marriages was unconstitutional.

Thompson’s fellow Pennsylvanian Rep. Fred Keller, also a Republican, cited Obergefell in defending his no-vote on the Respect for Marriage Act. It’s an unconvincing argument give the Supreme Court’s recent vote to overturn Roe v. Wade and Casey v. Planned Parenthood, erasing the federal right to abortion. Both Obergefell and Windsor were decided on a 5-4 vote, leaving it unclear whether the current court would balk at also trashing LGBTQ protections if given the chance. That risk becomes clear when you read Justice Clarence Thomas’s concurring opinion, where he specifically names Obergefell as a target for reconsideration among other “demonstrably erroneous decisions.”

It was in response to that uncertainty that House Democrats introduced the Respect for Marriage Act, which would fully repeal the Defense of Marriage Act (DOMA) and require states to recognize same-sex marriages conducted in other states. While that would still leave states free to ban new same-sex marriages should the Supreme Court reverse its previous decisions, those that have already been registered would be protected.

Without that protection, Thompson’s son and his husband would run into problems in Pennsylvania, which passed a law in 1996 that defines marriage as a “civil contract by which one man and one woman take each other for husband and wife.” That law holds that a “marriage between persons of the same sex which was entered into in another state or foreign jurisdiction, even if valid where entered into, shall be void in this Commonwealth.”

It remains incredible to me that Thompson could look his son in the eye after his vote.

That law is technically still on the books; in the case Whitewood v. Wolf in 2014, a federal court wouldn’t allow it to be applied, but that court’s decision relied on Windsor’s finding that DOMA is unconstitutional. Should that precedent fall, it’s likely Whitewood would as well, leaving Pennsylvania free to enforce its ban. Doing so could dissolve recognition of Thompson’s son’s marriage and others. The wording of the statute would also render them unable to travel to a different state to get re-married and have that union recognized in Pennsylvania.

Given those facts, it remains incredible to me that Thompson could look his son in the eye after his vote. I’ve emailed Stone, his press secretary, asking if the congressman supports the Pennsylvania General Assembly revoking the “one man, one woman” statute and why he seems so sure the Supreme Court won’t allow his son’s marriage to be annulled. As of Tuesday evening, she had not replied.

There is some hope that the Senate will also pass the Respect for Marriage Act. A number of Republican lawmakers say they will support (or at least not block) the House-passed bill. That still doesn’t excuse Thompson for his vote. He knew his son’s wedding was just days away, and 57 other Republicans voting for the bill gave him whatever cover he needed to support it, too. There couldn’t have been anything on his son and son-in-law’s gift registry nearly as a meaningful as Thompson’s “yes” vote would have been.

Hayes Brown is a writer and editor for MSNBC Daily, where he helps frame the news of the day for readers. He was previously at BuzzFeed News and holds a degree in international relations from Michigan State University.