TongueJoy
I was not aware, up until about five minutes ago, that they made vibrators you can strap to your tongue. The vibrator in question is called the TongueJoy, and the manufacturer's website offers it in what they call the Romance Edition.
The great thing about the TongueJoy is that it comes in a red satin ring box. I say go all the way. Take your special lady out to a sumptuous dinner, tell her how deeply you feel for her, then when the moment is right get down on one knee and pull out the box. I think you could tell a lot about your relationship from her reaction.