A fighter pilot goes to a bar after a good days flying. Whilst there he meets a young, attractive and available lady. She is charmed by his tales of aerial combat, high speed flight, and death defying feats. The inevitable happens and they slip away to somewhere more comfortable for an evenings intimate entertainment.
Much later that night the pilot drives home to his long suffering wife. On the way he puts on his oxygen mask and draws the straps up as tight as they will go. When he gets home he removes the mask and bravely enters the house. Immediately he tells the wife exactly and honestly what he has been up to that evening. She replies: "Do not lie to me, I can see you have been flying that damned airplane yet again".