Rubbish bags tear in sets of two (6)
I believe the answer is:
braces
'sets of two' is the definition.
'braces' can be an answer for 'sets' (brace is a kind of set). I am not sure about the 'of two' bit.
'rubbish bags tear' is the wordplay.
'rubbish' becomes 'bs' (vulgar abbreviation).
'bags' indicates putting letters inside (bag can mean secures or steals).
'tear' becomes 'race' (both can mean to rush or run around).
'bs' placed around 'race' is 'BRACES'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for braces that I've seen before include "Appliances to correct dental irregularities" , "straps to hold your trousers up" , "Support for trousers" , "Couples" , "Tighten" .)