(Strip Number 6051, Original Publication Date, 31 December 1988)
Panel 1: As one of the posts holding up the porch wishes the Pattersons a safe trip home, Elly (who is as covered in snow as the rest of the family) says goodbye.
Panel 2: As they drive to the airport, John and Elly complain about the horrible time they've had. He talks about how he spent two days thawing out the plumbing and the rest of the time there fixing farm equipment. Reason: he expected to relax, not to be put to work by his massive flapping anus of a brother-in-law Bleached Hayseed Thanos.
Panel 3: As Elly points out that the weather was awful, the kids fought and no one slept a wink, she notices that Mike is tearing up and asks why.
Panel 4: We're meant to think that he really had a wonderful time on the farm after all when he blubbers about why the wonderful times end so soon. The problem is that he's sad for a far weirder reason.
Summary: Said reason is not a foreshadowing of his telling Martha that he hates when his parents are right about things. The reason he's crying tears of sadness is that it's so rare that his parents openly admit to having made a big mistake when he's there to hear it.