Boys grabbing pet's front or back (7)
I believe the answer is:
sponsor
'back' is the definition.
(thesaurus)
'boys grabbing pet's front or' is the wordplay.
'boys' becomes 'sons' ('son' can be a synonym of 'boy'**).
'grabbing' is an insertion indicator.
'front' says to take the initial letters.
The initial letter of 'pets' is 'p'.
'sons' placed around 'p' is 'spons'.
'spons'+'or'='SPONSOR'
(Other definitions for sponsor that I've seen before include "One financially supporting event" , "One who backs" , "Financial backer" , "One paying to support" , "One offering support" .)