Delight when life model goes to town (8)
I believe the answer is:
felicity
'delight' is the definition.
(thesaurus)
'life model goes to town' is the wordplay.
'model' indicates an anagram.
'goes to' is a charade indicator (letters next to each other).
'town' becomes 'city' (I've seen this in other clues).
'life' is an anagram of 'feli'.
'feli'+'city'='FELICITY'
'when' is the link.
(Other definitions for felicity that I've seen before include "Joy -- eloquence" , "happy event" , "Intense joy" , "Girl" , "Complete happiness" .)