Stop making a boy sit awkwardly (6)
I believe the answer is:
desist
'stop' is the definition.
(desist means to stop)
'a boy sit awkwardly' is the wordplay.
'a boy' becomes 'des' (short for Desmond).
'awkwardly' indicates an anagram.
'sit' anagrammed gives 'ist'.
'des'+'ist'='DESIST'
'making' acts as a link.
(Other definitions for desist that I've seen before include "Stop, discontinue" , "Stop, whoa, give over" , "'Give over, refrain (6)'" , "Eject; annoyed" , "Cease; abstain" .)