A couple years ago, a friend of mine was really bummed about breaking up with his girlfriend, so he booked a trip to visit me in LA at the same time a bunch of "the guys" were also going to be in town, so that he could distract himself and have fun. He booked the trip about six weeks in advance, I think. However, just days before he was set to leave, he and his recent ex-girlfriend reconciled and got back together (probably because she was scared of what he would do on his mini-vacation).
When he got to LA, and saw all the beautiful, albeit retarded, women that this city had to offer, he found himself feeling a bit shafted, having suffered for over a month, missing his ex, looking forward to being a free man for this trip, only to have her take him back just days before his departure.
Thusly, we invented the ridiculously titled, Travelocity Rule of Retroactivity. (Rolls off the tongue, eh?) Said rule states, if you book a trip with the guys whilst single, even if you get a girlfriend before the time of the trip, you are single for that trip. That's a rule.