Kind of like floor porn. This involves the floor, another person and you doing really inappropriate things that can lead to STDs and babies you don't really want. Best to do this on a blanket.
It was 3:00AM in Chicago and I had just finished an amazing cherry slurpee from 7 Eleven. Chad was like "Lets have a floorsome and call it a night." I of course said yes! No one says no to a floorsome.
A number of people from a dormatory or residence hall that is fewer than a floorgy but more than simply floorcest.
Kara, David, and Karl has a floorsome in the sex box yesterday.