Recently, our daughter (17 in June) told my wife and me that she has started dating not 1, but 2 guys. No introductions needed since we already know them; they’ve been close friends of hers for quite some time now. Daughter put it as: why do I have to choose if I like them both and they don’t mind sharing?
I just don’t like it.
3 is a triangle; a love triangle. 2 is a line is you’re a religious but and don’t believe in sex before marriage. 1 is a point, of contention, if you’re a religious fanatic and don’t believe in masturbation.
You’re absolutely right about penta-amorous relationships.