"Why 'you knew what the deal was going in' is bullshit in relationships. Just because I knew the deal doesn't mean I am required to consent to it unendingly.
'Consent is a state of being. Giving someone your consent — sexually, politically, socially — is a little like giving them your attention. It’s a continuous process. It’s an interaction between two human creatures.'"
The article linked is about sexual consent in the context of what constitutes "real rape" and our current Rapist-In-Chief's endorsement of the new social climate of Rape Culture. But "you knew the deal going in" with respect to poly relationships is a natural extension of this same mindset, even if it's adjacent to the conversation about Rape Culture.
It's a coercive practice in the poly community where, usually, a cis-hetero couple lays down the law for some poor bisexual woman about what their relationship is going to look like once she signs her life away to them (sometimes not much different from the scene in 50 Shades, with actual contracts on paper and everything).
And then, when the woman who was initially snowed over with lust and New Relationship Excitement and the promises of double the fun by a, usually, more experienced couple, and not a little bit of strong-arming her to accept what would clearly be manipulative and toxic relationship practices in a monogamous context but who get away with it because it's "polyamory" so obviously it's going to look different so why can't "toxic" = "healthy" when we're turning the whole monogamous paradigm upside down ... ahem,
when this woman eventually starts to add up all the red flags and she can't ignore her misgivings any longer, or when she just changes her mind and her libido as people do over time and wants to renegotiate the parameters of her relationship *as we all have to over time*, the couple trots this old worn out trope and demands that she not ever change, that whatever she consented to previously still holds, and it's ALL HER FAULT for "disrespecting the primary" by daring to want something other than what she signed up for.
Consent, whether it's missionary sex in a long-term, hetero, vanilla relationship, casual hookup sex with the person you met in a bar, or ongoing intimacy in a poly relationship, is a continuous process and it is required *the whole time*, not just once up front. Expecting anyone to maintain a sexual, emotional, or romantic agreement they made in the past is coercive and a part of Rape Culture. Even when it's a couple doing it to a bisexual woman who "knew the deal going in".
"The problem is that technically isn’t good enough. 'At least I didn’t actively assault anyone' is not a gold standard for sexual morality, and it never was."
"Ideally you want them to say it again, and again, and mean it every time. Not just because it’s hotter that way, although it absolutely is; consent doesn’t have to be sexy to be centrally important. But because when you get down to it, sexuality should not be about arguing over what you can get away with and still call consensual."
"Rape culture describes the process whereby rape and sexual assault are normalized and excused, the process whereby women’s sexual agency is continuously denied and women and girls are expected to be afraid of rape and to guard against it, the process whereby men are assumed to have the erotic self-control of a gibbon with a sweetie jar of Viagra, creatures who ought to be applauded for not flinging turds everywhere rather than encouraged to apply critical thinking."
"The thing is, if you accept the idea a woman has the absolute right to sexual choice, you must also wrestle with the prospect that she might not make the choice you want. If she’s really free to say no, even if she’s said yes before, even if she’s naked in your bed, even if you’ve been married for twenty years, well then — you might not get to fuck her."
See how often these things apply to a couple's "third" when you mentally place them in these statements?