A bird never flew on one wing
Heard in Wexford, Longford and Monaghan
One should not limit oneself to a single romantic partner.
Q: "I see you were out with another young wan there the other night?" A: "Ah sure a bird never flew on one wing! ;-)"
'I see you were out with another young lady the other night?' 'Ah, quite so; a bird never yet flew upon one wing!'