The Freebie: Hollywood can't stand open relationships

I saw the trailer for The Freebie and it intrigued me. Here it appears we have a romantic comedy dealing with a couple venturing into an open relationship. The trailer even gave realistic looks into what brought the situation about and the couples' apprehensions. I was excited but also worried. I was worried that Hollywood would fall into the usual tropes of dealing with polyamorous love; that is it unrealistic and unacceptable. I still planned on seeing the film... Then I read this:

(SPOILERS AHEAD)


they have a huge fight in which they agree to violate their previous agreement and tell each other what happened. She says she did have sex with someone, he says he didn't and calls her a "slut" (which makes no sense to me). He takes off, she follows him and says she didn't really have sex, she would never do that (even though they agreed it was OK and he's the one in the wrong at this point). They seemingly reconcile. Then, we see a moment that may be a flashback moment in which they agreed to the freebie concept or which could be interpreted as a sort of alternate reality where they talked about the freebie but never went through with it, thus saving their relationship.

Bummer. The feelings that this couple experience that lead them to consider opening their relationship are average healthy feelings that I would wager all longterm monogamous couples deal with. Why can't the option of polyamory be explored in a healthy fun mainstream movie? I'm not suggesting that couples don't try it (which this fictitious couple did not do) and run into difficulties or even decide it isn't for them. Relationships whether monogamous or polyamorous are never simple and easy. I think we could find more than enough hilarious and heartwarming instances in a couple opening their relationship.