After a long hard workout on the stairmaster at the gym, one takes their pointer finger and places it between their nut sack and their leg. Then, you rub it around collecting this smelly, salty, sweaty, moist substance. Once this substance is on your finger, you now have Sandling Stinky Finger. This additive to your finger is generally used for things like giving wet willy's, lubricant to play with your balloon knot (Butt hole), or to simply suck on for a quick tasty snack.

Internet persona(s) who happens to follow you and you happen to follow them back and maintain communication with and have a mutual liking for eachother whether it be friendship wise, etc. (Mutuals if more than one mutual)