The accumulation of a copious amount of salvia around the base of the penis shaft, sometimes even dousing and soaking the ball sack, from a person that salivates heavily while giving head. May also be a result of intense deep throating action as well.
Steve couldn't believe how much bobber slobber Rhonda left on his man sack. His balls were drenched.
Jason got a slobber bobber from his fravorite knobber.