Serenades perhaps, and kisses with no upset (5)
I believe the answer is:
songs
'serenades perhaps' is the definition.
(serenade is a kind of song)
'with no upset' is the wordplay.
'with' indicates putting letters inside.
'no' becomes 'n' (common abbreviation).
'upset' becomes 'sogs' (I can't explain this - if you can you should believe this answer much more).
'n' going into 'sogs' is 'SONGS'.
'and kisses' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for songs that I've seen before include "Highish boot support" , "Lieder, chansons etc" , "Arias" , "Airs" , "Vocal compositions" .)