To slip someone the tongue

[Chicken Sandwich]

Be honest, Alan. You married the first girl who slipped you the tongue, didn't you?

What exactly does this expression mean? Does this refer to "French kissing" or just regular kissing or something else?

French kiss 1. n. kissing using the tongue;
open-mouth kissing.
What’s French
about a French kiss?
I didn’t know
whether I was going to get a French kiss
or a fish-kiss. 2. tv. to kiss someone using
the tongue.
Kids like to try to
French kiss each other at an early age. It’s
part of growing up.
He tried to French
kiss me, but I stopped him.

Thanks in advance.

 

[Ouisch]

Yes. "Slipping someone the tongue" is a slang expression for a French kiss. The dialog you quoted indicates that Alan was probably a "late bloomer"... very shy as a teenager/young adult, didn't go out with very many girls. Thus when he finally did meet a girl that did more than simply shake hands with him after their first and last date - a girl that gave him a very serious, sensual kiss - he was so afraid of losing her that he proposed marriage to her.