Down_the_Back
I once travled to Paris from BHX on my girlfriends passport! I took the wrong one by mistake! This was years ago, and after check-in went through the Euro Chanel, no one even looked at it. It was not until my return that I realized I had her passport. I did the same thing on my return, although I was terribly scared they may look at it!
People have sex changes - the girlfriend (ex) was certainly no looker, so I may have been able to get away with it) but there was no need after-all.
It would be a different story today of course, tightened security and all. But thought I would share this little story with you all!