Disheartened father intervenes, kindly, when they get a bit lively (6)
I believe the answer is:
frisky
'lively' is the definition.
(I've seen this before)
'disheartened father intervenes kindly when they get a bit' is the wordplay.
I cannot quite understand how this works, but
'father' could be 'fr' (abbreviation as in a priest's title) and 'fr' is present in the answer.
'bit' could be 'i' (resembles 1, a binary digit or bit) and 'i' is found in the answer.
The remaining letters 'sky' 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 frisky that I've seen before include "In high spirits" , "Frolicsome" , "Energetically playful" , "Playful, full of energy" , "Animated" .)