One girl and the other girl has to dip several tampons in different liquids, and put in the pussy off the blindfolded girl, and she has to guess in which liquid the tampon was dipped:

Suggestions:

Poprocks, Salt, Pepperseeds, Cayenne, Tabasco, Wasabi, Mustard, Sugar, Nettle, Toothpaste, Peppermint, Deodorant, Aftershave, ...