OP here, with an update with more information.
I saw my friend briefly this weekend and I asked him to please finish his interrupted story about Thanksgiving at his elderly aunt's house.
(For those who asked, my friend said that he heard that Larry moved in with the girlfriend around Christmas - but at Thanksgiving they were not living together.)
When Larry showed up at the door with the guest who he was told not to bring, the elderly aunt got very upset. My friend told me their aunt had Larry come with her into another room where she "chewed him out" very loudly for bringing a guest he had been told not to bring. Larry and the aunt left the door to that other room open, and the aunt's angry comments were heard by all, including the girlfriend.
After that, the gathering went on as before. Larry stayed, with his girlfriend, even after the angry comments from the hostess. An extra place was made at one of the tables and Larry and his girlfriend stayed for Thanksgiving Dinner.
My friend was upset with Larry for upsetting their elderly aunt, so my friend sat at a different table and didn't speak to Larry or the girlfriend. My friend said he felt like it was a very awkward meal when Larry and the girlfriend stayed on even after their aunt told him his guest was not welcome.
Comments? (I felt sorry for the girlfriend!)