Edit: I was wrong, this was just made up by college kids. See comment below.

Fun fact: In some college towns, they can only have fraternity houses but not sorority houses, because they still have laws on the books that define a house of prostitution as any house with at least three unrelated women living there.

Ackchyually… I think this is apocryphal.

https://www.snopes.com/fact-check/brothel-laws-sororities/