Originally Posted by mercury
It's kinda messed up that men can't make more of an effort to deal...
The core of the conversation is about the possessive nature of people in romantic relationships - I assure you that this issue of possessiveness is pervasive in men as well as women.
It is entirely possible that a person who has previously been monogamous can adopt another mindset regarding relationship pairing if they are exposed to this new ideology. Each individual is more likely to lean toward one pairing ideology over another; this is generally due to a combination of their genetic make-up combined with their environmental stimulus (this is true with any aspect of world view/personality).