Looking more embarrassed, going back and forth (6)
I believe the answer is:
redder
'going back and forth' is the definition.
'looking more embarrassed' is the wordplay.
I cannot quite understand how this works, but
'embarrassed' could be 'red' (someone may blush or go red when embarrassed) and 'red' is located in the answer.
The remaining letters 'der' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for redder that I've seen before include "Further to left" , "More inflamed" , "Blushing more" , "More revolutionary" .)