On a trip to Minsk with a male colleague who was one of the best and funniest people I have ever had the pleasure of working with, I went to my room after dinner and lots to drink, to find a dark brown mess on the pillows and sheets of my bed. The hotel was a total dump, pardon the pun, but this was quite unexpected.
After recoiling in disgust and then having a closer look, I realised that he'd sneaked into my room on some pretext, got hold of half a bar of chocolate I'd left on the side table, melted it on the radiator and smeared it over the bed!
In revenge, the next night, I went to a hooker bar and sourced the ugliest and most horrible crone I could find, gave her thousands of Belarus Rubles (worth about £5) and sent her to his room at 2 am.
The problem was that during the meetings we had the next day with the client, every time I looked at my colleague, I started laughing and found myself unable to speak properly. The Belarussians were rather dour and serious and clearly wondered what was going on.