Sweet D.e.s.i.r.e

Sweet D.e.s.i.r.e,

"You will regret this Mei Sou Fei!" cried Li Shimin Bide as he watches her clean close.
"Sweet d.e.s.i.r.e are like poison to one's soul," reply Mei Sou Fei while giving him one last sweet kiss.
Mei Sou Fei steps back and fell into the icy river below. Li Shimin Bide grabs his c.h.e.s.t as if he was in pain.
The cover is made graciously by @yaoyueyi
What happened to the two? What events led up to this moment?