A commotion behind you and me (6)
I believe the answer is:
rumpus
'a commotion' is the definition.
(I know that commotion can be written as rumpus)
'behind you and me' is the wordplay.
'behind' becomes 'rump' (informal term for the buttocks).
'you and me' becomes 'us' (the two of us).
'rump'+'us'='RUMPUS'
(Other definitions for rumpus that I've seen before include "Uproar or angry dispute" , "Noisy, disruptive commotion" , "To-do" , "Noisy disturbance" , "Harsh rough nature" .)