The girls were really on top after having won the next two games, and one of the guys complained about the teams - 7 to 6 was unfair. The girls on the other hand were really happy with the teams. I then dropped the suggestion "let's play strip volleyball then". Losing team have to drop one item of clothing every time they lose a game.
As expected, the german girls were game, the american ones a bit thoughtful and the HK girl didn't dear to say anything. When one of the guys opinioned against it the jap girl voiced her support and then it was decided.
I had already pointed out to the guys that for this to work we'd have to maintain uncertainty about the outcome as long as possible - but we were also one piece of clothing behind the girls (we all wore just shorts, briefs and a t-shirt, the girls with a bra as well). So, needless to say, next game we played much better than before, but whenever we were 2 points ahead we made sure to lose one to keep the girls thinking they had a chance. (most of us guys were a good deal sportier than the girls and several were playing volleyball regularly for fun at uni)
So, after first game the girls lost and decided to drop their t-shirts. Then we "just" lost the next game - and decided to drop our shorts
The next game we lost again - unintentionally - and dropped our t-shirts. The girls were really excited and looking forward to seeing us naked next time. We were getting a bit worried.
I then proposed we should make another rule - when one team lost both teams'd have to play to get their clothes back. That way I figured we could get to look at the girls for a while - if we at least could get their bras off