Many explanations led back to Scotland and Sir Walter Scott. I've read a few novels by Scott, and can't remember any tongue and cheekiness, just long winded disortations, and very little dialogue. Defenders of Scott can speak up ..

I'm glad you posed this question, it's quite intrigueing where they come from . .

Mr. Laotzu92, I remember you from the old planet .... good to hear from you.

Monique ..

The best explanation I found is at this link . . .

http://www.wisegeek.org/what-does-tongue-in-cheek-mean.htm

I think in conversations that are light and fun, you will find a lot of quips, jabs, or queries that help to liven a conversation to keep it from becoming pondervous ..

Monique

yes, I did, and I remember you as being a very polite and courteous gentleman . . .

I think it's about prodding your tongue into your cheek so you don't laugh out loud. I do this a lot, but maybe it's not common.

Monique is correct-and thanks for the link! If you do the physical act of pushing your tongue into one of your cheeks (it's always the left for me), you'll get the idea of why it is used for making the ironic joke.

bows in direction of Ms Monique. Did You have same name on old planet?