Tears flowing: that's shocking (5)
I believe the answer is:
taser
'that's shocking' is the definition.
'tears flowing' is the wordplay.
'flowing' indicates anagramming the letters.
'tears' is an anagram of 'TASER'.
(Other definitions for taser that I've seen before include "Police stun weapon" , "Weapon used to deliver a temporarily paralysing electric shock" , "Shocking device used by the police?" , "shocker" , "Shocking weapon" .)