Sheepish fake journalist's drinking mug (10)
I believe the answer is:
shamefaced
'sheepish' is the definition.
('shamefaced' can be a synonym of 'sheepish')
'fake journalist's drinking mug' is the wordplay.
'fake journalist' becomes 'shamed' (I can't justify this - if you can you should believe this answer much more).
'drinking' is an insertion indicator.
'mug' becomes 'face' (I've seen this before).
'shamed' placed around 'face' is 'SHAMEFACED'.
Can you help me to learn more?
(Other definitions for shamefaced that I've seen before include "Sorry-looking" , "Showing guilty embarrassment" , "Sheepish" , "Looking humiliated" , "Red" .)