Issue with anything set up to deceive (3-4)
I believe the answer is:
two-time
'deceive' is the definition.
(I know that two-time is a more specific form of the action betray)
'issue with anything set up' is the wordplay.
'issue' becomes 'emit' (both can mean to give out or radiate).
'with' means one lot of letters go next to another.
'anything' becomes 'owt' (owt means anything in Northern English dialects).
'set up' shows that the letters should be reversed in order (in a down clue, letters go up).
'emit'+'owt'='emitowt'
'emitowt' back-to-front is 'TWO-TIME'.
'to' is the link.
(Other definitions for two-time that I've seen before include "Be unfaithful to (a partner)" , "Deceive slangily - twice?" , "Double-cross (a partner) - recurring once" , "take her for a ride" , "Be unfaithful to a lover" .)