Well, there wasn't any tongue..
Think of it like Who Framed Roger Rabbit. Just a big fat "Thank you for being such a wonderful person" kiss.
I have a best friend (however she's female) and this kind of thing goes on all the time... She has a boyfriend too, but he's totally understandable of our platonic closeness.
You never know though... One night... after a few shots... things get a little hot... Your perspective might change. But if you're truly as close to her as you say you are, nothing should change your foreverfriendship.
Peace, havva nice trip.