The Game of Hidden Pleasures. Once, Twice, or as often as you like! Why not spice things up a bit? You and your lover each exchange a hidden I.O.U. Secretly place one in his jacket pocket so he will discover it later at work - or tuck one into his suitcase so that he'll find it when he unpacks at the hotel. With I.O.U., you will learn new bedroom tricks and variations on the old ones.