Future groom working in café (6)
I believe the answer is:
fiance
'future groom' is the definition.
(I've seen this in another clue)
'working in cafe' is the wordplay.
'working' is an anagram indicator.
'in'+'cafe'='incafe'
'incafe' is an anagram of 'FIANCE'.
(Other definitions for fiance that I've seen before include "One getting married" , "Man engaged to marry" , "He's engaged to be married" , "One waiting to go to match" , "The man she is going to marry" .)