Maybe this is just me. I have had this conversation with a few friends who have all said "Margaret Thatcher"! WHY THE HELL would you want to think of her when you're in the middle of, well, that?
My thing is to just carry on - if you happen to, er, "arrive" sooner than anticipated, well then you have a 5 minue break, a bit of a snuggle while you catch up, and then you go again... Repeat until you're both tired and fall asleep!