The practice of reforming a portion of a memory foam mattress into a shape resembling an orifice in order to fornicate with same. A true topgrading is done to the mattress of another in order to exact some form of revenge (see, eg. "top shelf
" or "upper decker
" et al.)
"Garret's topgrading session was interrupted by a mirror crashing down from Trisha and Brad's wall. He nonetheless reached climax and decided this had made it all the more satisfying."
When a lower bunkmate masturbates to the intercourse occurring on the bed above him, and tries to hit the above mattress with his spunk
"Brad never gets laid, but I often hear him topgrading down there, while I fuck my girlfriend.
The mid-coital act of assessing a woman's performance, while she is engaged in the cowgirl position.
"I was getting close to busting a nut, but she got pissed off when I topgraded her, and she stormed out."
"My pregnant wife always cries, when I start topgrading her, yet she wants me to be more open with my feelings - and what just started to happen there, didn't FEEL as good as when my girlfriend does it."