First, I have normal human sexual hunger, and I can enjoy reckless passion, but I have always been able to find this in the context of committed, loving, relationships. In other words, I prefer making love to f***ing and scr**ing "around," but I am glad to f*** and scr** the person that I love, if the lover and the desire and the commitment seem to be totally mutual. I guess it's mostly about trust, and the premise of this movie is that two people who REALLY trust each other to keep loving each other could agree to F & S "around" with others, as long as it was "just sex."
ALTERNATIVE PROMISED IN THE REVIEW TITLE:
For a more in-depth and believable exploration of the idea of sex with others in the context of a committed relationship, I recommend the Swiss-language* series Monogam-ish. Not the movies with that title. The 2-season, multi-episode series has enough time to really develop the characters, and to show every stage of what would likely happen to a committed couple if they chose to have an "open" relationship.
* Swiss language is an interesting combination of German, French, Austrian, Italian, Spanish, and English (think Spanglish and Franglais, but on steroids), so if you understand at least English and one of these other languages, you may not need to read the English subtitles to get what is going on. I know watching foreign-language movies is not as easy as watching movies in your native tongue, but this series is truly worth the effort.
DETAILED DISCUSSION ABOUT FLAWS IN THE MOVIE SEEING OTHER PEOPLE
The movie-making, itself, is fine. My issues are with the premise and the story behind the screenplay. As I already mentioned, for me (and I, suspect, for most people, whether or not they realize it, any fulfilling sex involves connection, and connection requires trust. So when this couple attempts to have sex with "others," they are both subtracting from their mutual relationship (less time, less sex (in the long run}, and Iess trust that they can still give to one another), and giving some of that to these other relationships, no matter how "meaningless" that sex with "others" is intended to be.
The more obvious example of this is how the woman finds ONE other man and discovers that repeated sex and time spent with that other man turns into an unintended relationship.
The less obvious example is how her fiancée, when trying to follow her suggestion of sleeping with others (a suggestion which starts out with self-serving intentions on her part), finds himself only able to pick up sex dates when he first opens up with intimate details about himself...in other words, he has to create the connection of the beginning of a relationship with each new woman, before he can succeed with so-called casual sex.
I DON'T believe that a truly committed couple...
A) would jump right past trying some sexual fantasy and sexual experimentation WITHIN their relationship, instead going to the extreme of extra-relationship sex
B) would try to maintain their original committed relationship, if it was clear that relationship was not "enough" for either or both of them, because that's the kind of thing that people take personally, as in "If I'm not enough for you, no matter how hard we try, then this is over," and
C) would both, essentially "cheat" on their relationship, even if you don't consider it cheating on one another in a situation where there is mutual advance consent, and THEN somehow believe that they can put their relationship back together, without always wondering whether one another will cheat on them, or cheat on the relationship, again.
Again, this story MIGHT happen in real life, but not in a relationship that involves me!