I felt awful eating the last bit of your pudding (6)
I believe the answer is:
trifle
'pudding' is the definition.
(I know that trifle is a type of pudding)
'i felt awful eating the last bit of your' is the wordplay.
'awful' is an anagram indicator.
'eating' indicates putting letters inside.
'the last bit of' says to take the final letters.
The last letter of 'your' is 'r'.
'i'+'felt'='ifelt'
'ifelt' with letters rearranged gives 'tifle'.
'tifle' going around 'r' is 'TRIFLE'.
(Other definitions for trifle that I've seen before include "Dessert; act frivolously" , "Party dessert" , "one's last course" , "Treat frivolously" , "Pudding - bagatelle" .)