just played it and made it all the way to the money shot. definitely nsfw, and not a very good tetris game either. good effort, though.
There's a more traditional tetromino game called "Strip Tetris". I played it for a while. I never got the hang of Sextris. I couldn't figure out the precise rules for when the pieces would "couple" and disappear.
the rules are simple. either sex organ between legs to sex organ between legs, or both mouths between the other person's legs.
umm, it's a little more complicated than that. http://www.eiu.edu/~lewclark/06/sxconcept.html you have to use your imagination i guess