The vaginal wetness and moisture that does not appear to be present until an object, finger, penis or other body part is stuck inside the vagina. After which, like a tap for tree sap, allows the wetness to flow out freely thus creating Vag Sap.
Hey dude. I hear your girlfriend has a dry snatch. No way braaa. It may seem that way but once you get a finger in there, nothing but pure Vag Sap. Sweet!