Pair watch unfaithful lover (3-5)

I believe the answer is:

two-timer

'unfaithful lover' is the definition.
(I've seen this before)

'pair watch' is the wordplay.
'pair' becomes 'two' (I've seen this before).
'watch' becomes 'timer' (I've seen this before).
'two'+'timer'='TWO-TIMER'

(Other definitions for two-timer that I've seen before include "Double-crosser" , "Unfaithful partner" , "Unfaithful person" , "Unfaithful lover in arithmetic mode" , "One sleeps around" .)

I've seen this clue in The Sun.

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