Tina's upset when Eric's naughty - and very quickly! (2,1,5)
I believe the answer is:
in a trice
'very quickly' is the definition.
(I've seen this in another clue)
'tina's upset when eric's naughty' is the wordplay.
I cannot really understand how this works, but
'when' could be 'e' (I've seen this in other clues) and 'e' is located in the answer.
an anagram of 'tina' is 'inat' which is within the answer.
This explanation may well be incorrect...
'and' acts as a link.
Can you help me to learn more?
(Other definitions for in a trice that I've seen before include "quickly" , "Pronto" .)