Smile after tea shows anything but delight (7)
I believe the answer is:
chagrin
'anything but delight' is the definition.
(I've seen this before)
'smile after tea' is the wordplay.
'smile' becomes 'grin' (synonyms).
'after' is a charade indicator (letters next to each other).
'tea' becomes 'cha' (cha is a type of tea).
'grin' put after 'cha' is 'CHAGRIN'.
'shows' acts as a link.
(Other definitions for chagrin that I've seen before include "Annoy" , "Shame at one's failure" , "Arching with annoyed disappointment" , "Shame at having failed" , "Feeling of vexation or embarrassment" .)