Title text: Except the people filtering in late are the partiers, so you end up with drunken makeouts in the living room and the next roommate to return home has to sleep in the hall lounge orbital.
This is a pun on the Pauli exclusion principle, a principle that two identical fermions (particles with half-integer spin like electrons) can not be in the same quantum state at the same time and location.
In this case, the guests are the electrons, only two people can share a single room (or orbital, describing the probability of finding an electron in a given space). But the different spins here are just the different chromosomes of females and males. The roommate, female or male, has to occupy an other orbital, because there are only two available spin states possible for fermions: +1/2 and -1/2.
The title text jokes about drunken party-goers, ignoring the Pauli principle, partying and sleeping together with many people in the living room. The roommate ends up in the hall lounge.
- [Cueball is holding up a pointer in front of a diagram of a dorm apartment. On the diagram, there are two connected pairs of dots in each bedroom, and one dot on the couch.]
- Cueball: Thus, once all the dorm bedrooms are occupied by romantic pairs, additional roommates are forced into less restful "living room couch" orbitals.
- The Pauli Sexclusion Principle