Tease a twerp (4)
I believe the answer is:
twit
I believe this clue is a double definition.
'tease' is the first definition.
(I know that tease can be written as twit)
'a twerp' is the second definition.
(I know that twerp can be written as twit)
(Other definitions for twit that I've seen before include "Bait - fool" , "Silly fool" , "Slangily a foolish person" , "Taunt; fool" , "Ninny" .)