Bassett did the same thing.. she (this is gross and funny) would suck on the end of her tail until it was sopping wet, and then get up and whip it around, many times hitting me in the face!! A wet tail hurts a lot, like a wet towel hurts more than a dry one! I ended up buying some gross tasting stuff from the vet and put it on her tail to make her stop. However, I'm sure you don't want that stuff all over your shirts I know it can be really annoying and gross.. you may want to ask your vet for advice.