Receiving a blow job from someone with no teeth (hence the gummer), while taking a shit on the toilet (hence the blumpkin).
Donald was the most delighted when ol' Betsy from room 309 came down the hall before midnight and surprised him with a Gummer Blumpkin on his birthday; needless to say, that's one way to keep the Doctor away!
When one puts their mouth on a muffler of a gas powered vehicle. Than proceeds to crap out their anus.
Ian had a hard day at work. When returning home before shutting off the car he stripped down and got down on all fours. Than proceeded to give his car a muffblumpkin.