On account of two playing together love ensues (3,2)

'on account of' is the definition.
(both can mean 'as a result of')

'two playing together love ensues' is the wordplay.
I cannot quite understand how this works, but
'two' could be 'duet' (duet is a kind of two) and 'duet' is found in the answer.
'love' could be 'o' (love means zero in tennis) and 'o' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).