as stated above by Trippin 2.0
" if it was something that you can forge between numerous people equally, then there's nothing special or intimate about it."....
yep. And i would add to that, why bother being in a relationship then? why have a Marriage or a Girlfriend? Why not just have a random assortment of bodies to entwine with?
Is it because ultimately one still wants to feel as though there is ONE special person for them?
Where does the line get drawn? So your wife finds a handsome young man that she starts bumping uglies with, and through that intimate physical act, she learns to care for him and he for her, and perhaps when you would like her home making dinner, she is at his house, in his bed, discussing his day with him, offering him emotional support while you sit at home in an empty house.... Then what? Do you make a call and go to a girl who takes on the role as 'satisfier'? And then wife comes home one day and you are not there for her... so she looks elsewhere... Like, what's the point?
If there is no emotional investment in sex, if there is no intimacy, and its just mechanical action, then who cares if you have the same person daily, or a blow up doll.
If it's because you like variety, then why bother having a Wife or Girlfriend?
I mean, i understand the desire to be with other people, but there are a variety of ramifications and i think that the opinions of others, as to why they are monogamous have been swept to the side by you as being absurd or wrong. Not cool.