Desire to tell you spoilers about finales (4)
I believe the answer is:
lust
'desire' is the definition.
(I know that lust is a type of concupiscence)
'tell you spoilers about finales' is the wordplay.
'finales' indicates one should take the final letters (I've seen 'finale' mean this).
The final letters of 'tell you spoilers about' are 'LUST'.
'to' is the link.
(Other definitions for lust that I've seen before include "One of the seven deadly sins" , "Deadly sin of extreme passion" , "Passionate desire" , "Lecherousness" , "Intense sexual desire, a deadly sin" .)