Never knew of this one...but yeah, I can see how that's vulgar (if you can't find it under Grass-Mud Horse, look for Cao Ni Ma). Actually it reminds me of something I read a long time ago about a song (Mei Hua/ 梅花). It used to be considered a song with political overtones... and now they come up with stuff like this... Tells you how the young have evolved over the years...