The act of sticking your finger up a wet vagina and promptly sticking it into another person's ear

Got the covid-19 vaccine

A Moist William is the act of barely inserting your erect penis tip inside an excited girl's wet vagina, promptly pulling it out and sliding the residual vaginal fluid on her inner thigh. The movement should be done in a swift "paint-brush" fashion. After this, for the Moist William to be complete, put your clothes back on, pack your belongings, leave without saying a word, and never call her back.