The act of incrementally moving, sliding or scooting one's derrière, buttocks or rear along when sitting on a sofa or bench, usually to make room for others to sit.
Schlochenthorp is a sex move which takes no less than three years to complete and there is absolutely NO sex to be had. It contains 849 highly detailed steps that must be followed to the letter. A full list can be found on Facebook. It can be performed solo or with multiple people.
I haven't seen John lately. Where is he?" "He is off performing Schlochenthorp with his girlfriend. He won't be back for a while"