A prevailing and pervasive Chinese slang referring to the asshole since their verisimilar figures. Firstly used on the web by slash fans then went householding across the country due to its subtly, vividity and artistry that suits both refined and popular tastes. Usually used between boys when badinaging and mostly strongly relating to an anal sex, which is a form of sex often happens between gays. The most famous collocation is to "explode one's chysanthemum" which means to shove a penis, a dildo, a cob or whatever it is into someone's asshole and get it bloody as a result.
My chrysanthemum itches.
I'm gonna get your chrysanthemum imploded.
Wash your chrysanthemum and wait.