"A penny for your thoughts" joke

A young Scottish lad and lassie were sitting on a low stone wall, holding hands, and just gazing out over the loch. For several minutes they sat silently, then finally the girl looked at the boy and said,"A penny for your thoughts, Angus."
"Well, uh, I was thinkin'... perhaps it's aboot time for a wee kiss."
The girl blushed, then leaned over and kissed him lightly on the cheek. Then he blushed.
The two turned once again to gaze out over the loch. After a while the girl spoke again. "Another penny for your thoughts, Angus."
"Well, uh I was thinkin... perhaps its noo aboot time for a wee cuddle."
The girl blushed, then leaned over and cuddled him for a few seconds. Then he blushed.
Then the two turned once again to gaze out over the loch. After a while the girl spoke again. "Another penny for your thoughts, Angus."
"Well, uh I was thinkin... perhaps its aboot time you let me poot ma hand on your leg."
The girl blushed, then took his hand and put it on her knee. Then he blushed.
Then the two turned once again to gaze out over the loch. After a while the girl spoke again. "Another penny for your thoughts, Angus."
The young man knit his brow. "Well, now," he said, "My thoughts are a bit more serious this time."
"Really?" said the girl in a whisper, filled with anticipation.
"Aye," said the lad.
The girl looked away in shyness, began to blush, and bit her lip in anticipation of the ultimate request.
"Din'na ye think it's aboot time ye paid me the first three pennies?"