Close friends of the opposite sex?

[The Red Pill]

I am sure that this has been posted on the forums before but I wanted to see if I can get some of your insight to a question that has been piquing my interest for some time. Issues of jealousy always seem to arise when your SO or you has issue with each others close friends of the opposite sex, or for gay couples the same sex...or vice versa. If you have close friends of the opposite sex how do approach this so as not to concern or make your partner jealous? Furthermore, how can you ensure that your friendships don't become inappropriate and enter into the slippery slope of what can be categorized as an EA (which usually ends up in a PA anyways)? Even more harrowing is how do you approach an issue where a close friend of your SO seems to be just hanging on waiting for the other shoe to drop for an opportunity to hookup with your SO? Finally, how do you mitigate your own jealously if your partner has a lot of close friends that could be potential mates, and what does that say your partner, if anything?