No It is not ok to put sharpie on your tongue why would you do that
Here goes some information its not bad or anything but here Is it bad to put Sharpie in your mouth?
While Sharpie markers are AP-certified non-toxic, we do not recommend using them on areas of items that may come in contact with food or the mouth. Sharpie has not been tested as an oven proof product and should not be used anywhere where a consumer could possibly ingest the ink.