Once you find someone that you love, you feel a sense of ownership, for lack of a better word. There's no way I'd be able to function if my significant other slept around- I'd feel that with every other sexual partner, they'd become less 'mine.'
Open relationships also create the idea that you aren't enough of a man/woman to satisfy your partner on your own. Complex much? If it genuinely goes both ways, it sounds like both partners are more focused on sex than love/intimacy, and therefore should probably just stay swingin' singles anyway.
Sex with intimacy is far more fulfilling in the long run than a one night stand. Like someone up there said, if your partner isnt comfortable with 'spicing things up,' you aren't sexually compatible and should review your relationship.
Open relationships also create the idea that you aren't enough of a man/woman to satisfy your partner on your own. Complex much? If it genuinely goes both ways, it sounds like both partners are more focused on sex than love/intimacy, and therefore should probably just stay swingin' singles anyway.
Sex with intimacy is far more fulfilling in the long run than a one night stand. Like someone up there said, if your partner isnt comfortable with 'spicing things up,' you aren't sexually compatible and should review your relationship.