A butterfly kiss is when someone flutters their eyelashes up against your cheek.
My informant says she learned this from her aunt as a child. She believes it is called a butterfly kiss, because it is such a light, delicate touch, like that of a butterfly landing on one’s hand. It is also a little ticklish.
I agree with her explanation, as well as the motion of fluttering, is a term used on particularly butterflies and eyelashes. A butterfly flutters its wings, and usually a woman flutters her eyelashes. Fluttering is a motion considered very soft, and feminine. So a butterfly kiss is as well. It is a little gesture of innocence and love.
The term butterfly Kisses was also used by country singer Bob Carlsie, in his song “Butterfly Kisses” where he sings about the growth of his daughter and their relationship,
“Oh with all that I’ve done wrong
I must have done something right
To deserve a hug every mornin’
And butterfly kisses at night”