Look! Young man is retreating! It’s a source of embarrassment! (7)
I believe the answer is:
scandal
'embarrassment' is the definition.
(thesaurus)
'look young man is retreating' is the wordplay.
'look' becomes 'scan' (I've seen this before).
'young man' becomes 'lad' (I've seen this before).
'is retreating' says the letters should be written in reverse.
'lad' in reverse letter order is 'dal'.
'scan'+'dal'='SCANDAL'
'it's a source of' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for scandal that I've seen before include "subject for play school" , "Outrageous event" , "content of 3 [RED TOPS]?" , "Public outrage; gossip" , "Subject of Sheridan's school" .)