1. When a fat man is fucking a skinny woman
from the back but has to "
shelf"(rest) his stomach on her ass or
lower back2. When a pregnant woman has to rest her stomach on a table
Example 1. Tom: Dang, Sheryl must have serious back problems!
Denise: Why's that Tom?
Tom: Because Sheryl gets
shelfed by her fat ass husband
more than a used book at a bookstore.
Example 2. Husband: Hey honey, do you need to stop and rest for a bit?
Pregnant wife: Yeah let me shelf on this
picnic table really quick.
(variations include: shelf ,
shelved, shelving)