Choreographed a sexed-up Boxing Day dance (3,2,4)
I believe the answer is:
pas de deux
'dance' is the definition.
(pas de deux is a kind of dance)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for pas de deux that I've seen before include "duet" , "Nutcracker part" , "Ballet sequence for couple" , "Steps" , "Dance for a couple" .)