Gleam in your eye

A couple was walking across the meadows. The girl looked at the guy and shyly asked, "Would you like to hold my hand?"
"Uh...well yes." the boy said, "But how did you know?"
She said, "By the gleam in your eye."
They walked a little further and the girl said, "Would you like to kiss me?"
"Oh, my yes!" replied the boy, "But how did you know?"
She said, "By the gleam in your eye."
As they got to the stream, they sat on a stump, the girl looked at the boy and asked, "Would you like to go all the way with me?"
"Well, oh, my gosh, yes! (gulp) Yes! But how did you know? By the gleam in my eye?" he asked.
"No," replied the girl, "By the tilt in your kilt."