When one removes their comments in a thread of online conversation that ended with them looking stupid or otherwise badly.
"Did you see that girl who was commenting on Robert's facebook about Erin's pregnancy who thought that 7cm dilated was 'a lot of personal information' and ended up getting schooled on what happens when people have babies?"
"Hell yeah she looked even worse after she ended up pulling a granlund"
"Pulling a granlund?"
"Yeah. You know, when people delete all of their comments and pretend they never looked like a total ass"
A reference to the Highlander plotline, when one immortal kills another in an act of decapitation, the immortalgasm is when the victor is subsequently engulfed by what can only be described as a painful ecstasy, whilst they are enveloped by a torrent of wind, a blinding light and (often) a mysterious force that takes the form of lightning.
"Hey dude pause your tivo, I have to take a leak and I think he's pretty close to immortalgasm!"