We did this Sunday, during the Eagles-Giants game. Yes, that game. We left when the Eagles were down by 21 (I think). My niece had been bugging us all day, unable to be patient, so we decided to stop watching the massacre and get her present out of the way. We spent a delightful hour shopping and then got into the car and turned on the radio just as the Eagles won the game on the most amazing play of all time.
Yup, we diehard Eagles fans missed the best Eagles game that will happen during our lifetime. Teh Hubby turned off the radio and sat facing forward, turning purple and vibrating slightly. My niece says, very quietly, "I'm sorry Uncle [blank]. I'm sorry I made you miss your game."
At which point he turns around, plasters a smile on his alarmingly purple face, and says, "It's okay. I'd rather make you happy," and then turns back around before he loses his fake smile.
I've never seen my niece more radiant. That's Christmas. Probably arterial damage as well, but Christmas.
[edited for clarity]