Behave indecisively when fool takes drug in front of girl doing the same (6-6)
I believe the answer is:
shilly-shally
'behave indecisively' is the definition.
'fool takes drug in front of girl doing the same' is the wordplay.
I cannot really understand how this works, but
'drug' could be 'h' (H is an example) and 'h' is located in the answer.
'fool' could be 'silly' (synonyms) and 'silly' is found within the leftover letters.
'girl' could be 'hally' and 'hally' is located in the answer.
A single letter 's' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'when' acts as a link.
(Other definitions for shilly-shally that I've seen before include "Vacillate" , "Dither" , "Be indecisive" , "Procrastinate" , "Hesitate" .)