Maybe Matt and Luke Goss keep those small bottoms clenched in (7)
I believe the answer is:
gospels
'maybe matt and luke goss' is the definition.
I can't judge whether this defines the answer.
'keep those small bottoms clenched in' is the wordplay.
'bottoms' indicates one should take the final letters (I've seen 'bottoms of' mean this).
'clenched' becomes 'goss' (I am not sure about this - if you are sure you should believe this answer much more).
'in' is an insertion indicator.
The last letters of 'keep those small' are 'pel'.
'pel' going within 'goss' is 'GOSPELS'.
Can you help me to learn more?
(Other definitions for gospels that I've seen before include "Part of the New Testament" , "Religious narratives" , "Four New Testament books" , "eg Mark, Luke etc" , "Matthew, Mark etc" .)