Exactly one of Sam or Tom has family visiting. They make these statements:
Sam: "Tom has family visiting, but I don't."
Tom: "Sam is lying, or I am lying, or possibly we're both lying."
Which of the two men has family visiting?
Attribution: this puzzle is from The Mensa Puzzle Calendar, July 17, 2018. I solved it as intended but the solution doesn't sit right with me. I want to see what other solutions can be found.