When (one) was a twinkle in (one's) father's eye phrase
This phrase refers to the time before one was born into this world.
I never knew my father's parents as they passed away when I was a twinkle in my father's eye.
His brother died in a car accident when he was a twinkle in his father's eye.
She believes every day of her life had already been written on God's calendar when she was a twinkle in her father's eye.
From a song, "When You Were a Smile on Your Mother's Lips (and a Twinkle in Your Daddy's Eye)", written for the 1934 film, Dames; derived from the presumption that prior to the conception of a baby, the father was sexually aroused, and this arousal was reflected in a pleased look in the father's eyes.
People tend to like forbidden or illegal things just because they are forbidden or illegal.
He must have believed that stolen fruit is the sweetest, and he, therefore, cheated on his partner.