secLUEsion 

A day when hell broke loose because Ceejus made LUE secret.

What a secLUEsion today was!

secLUEsion by Joe October 12, 2003

Sexclusion

When two out of three people in a group are in a flirtatous mode and obviously want to bang each other while completely exluding the third wheel.

While Bettie and Harold fondly caressed each other, Greta was in the corner feeling pangs of sexclusion.

Sexclusion by Stephanie Anne Brock November 10, 2008

sexclusion principle 

When determining where to place electrons in atoms, three rules are generally used: the Pauli exclusion principle, the Aufbau principle, and Hund's rule. The Pauli exclusion principle, from which the pun is derived, states that no two electrons (or indeed any fermion) can occupy the same atomic state. Therefore, any electron orbital is limited to two electrons: one with a spin, and the other with a − spin. The Aufbau principle states that lower energy orbitals are occupied previous to high energy orbitals. Hund's rule states that electrons will try to fill orbitals individually, and only pair up when every orbital has a lone electron in it.

In the comic, electrons are being equated to people, and rooms (or couches) are equated to orbitals. The reverse of Hund's rule is then followed: people will try to pair up in a room first, and only when all the couples have done so will rooms be allocated to single people. The Pauli exclusion principle here means that only two people can occupy a room at a time (should those people be romantically involved). The Aufbau principle therefore means that more restful rooms are filled previous to less restful rooms.

The title text jokes about drunken party-goers, who ignore the Pauli principle perhaps out of inebriation. They then end up partying and sleeping together with many people in the living room, leaving the roommate stuck in the third desirable location, the hall lounge.

See xkcd.com/658/ for visual diagram of Pauli's Sexclusion Principle

sexclusion principle by Bad C dev September 20, 2021

Sexclusion

When two out of three people in a group are in a flirtatous mode and obviously want to bang each other while completely exluding the third wheel.

While Bettie and Harold fondly caressed each other, Greta was in the corner feeling pangs of sexclusion.

Sexclusion by Stephanie Anne Brock November 10, 2008

Selusionex 

A delusional ex you want to auction to the lowest bidder.

Honey sugar my selusionex from Jersey City showed up this holiday season from the blue saying you must be so hard and wet for me; Forget I crushed you being a total loser and douchebag the last time I texted or that was fifteen years ago given time just moving forward with no two tones about it.

Selusionex by ilacevoli December 9, 2018

Selusionex

A delusional ex you want to auction to the lowest bidder.

I held an auction for my selusionex hoping for a 0 cent bid.

Selusionex by ilacevoli January 1, 2026