势成骑虎 shì
chéng qí hǔ
It's hard to dismount a tiger
photo of tiger taken at Kok Lawi Wild Life Park, Sabah
势成骑虎 shì chéng qí
hǔ is achengyu (Chinese Idioms).
It describes the dilemma or the situation one
is in when one faces the difficulty of stopping midway after
having embarked (started) on a project".