Secretly responsible for the embarrassing displays of emotion (6,3,6)
I believe the answer is:
behind the scenes
'secretly' is the definition.
(I've seen this in another clue)
'responsible for the embarrassing displays of emotion' is the wordplay.
'responsible for' becomes 'behind' (I've seen this before).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'embarrassing' becomes 'he' (I can't explain this - if you can you should give a lot more credence to this answer).
'displays of emotion' becomes 'scenes' (I've seen this before).
'behind'+'t'+'he'+'scenes'='BEHIND THE SCENES'
Can you help me to learn more?
(Other definitions for behind the scenes that I've seen before include "Privately" , "backstage" , "Where stage hands work" , "Playwright is" , "responsible for acts, partly" .)