#westermarck effect

In cases of GSA (eg, Patrick Stübling and Susan Karolewski), consent is not an issue because the two weren’t raised together, so they did not have a familiar power dynamic growing up. Siblings who’re reared together, however, do. While as I pointed out here (section 1), parent-child relationships by nature have a far greater imbalance of power than sibling relationships; however there is still an inherent and far more complex power imbalance at work based on age-rank dominance, and for a sexual relationship to be truly consensual, there can be nothing of the sort. In theory, older siblings are expected to protect, defend, aid, and teach younger siblings, who are in turn expected to obey older siblings (though not to the exclusion of a parent or other authority figure who outranks the elder sibling). In practise, older siblings are sometimes demeaning, manipulative, and domineering towards our younger siblings, who in turn often manipulate others against their elder siblings. Elder siblings often resent younger siblings “always getting their way” while younger siblings often resent elder siblings being perceived as more mature or responsible. This is NOT a relationship of equals.

Because of this, sibling incest is inherently manipulative. If the younger sibling is the one pursuing the older it plays on the older sibling’s ingrained (by which I mean learned, not necessarily instinctive, though that can also be a factor) sense of responsibility to tend to the needs of the younger. If the older sibling pursues the younger it takes advantage of age-rank dominance, the younger’s ingrained notion that the older must be obeyed – I’d argue this is even more problematic because it’s closer to coercion than seduction.

I mentioned earlier than non-GSA sibling incest is abusive. That doesn't necessarily mean that one sibling beats the other: there are many forms of abuse. It's because a relationship in which one party has been coerced or otherwise manipulated into entering rather than doing so voluntarily is by definition abusive. As much as I would like to erase all knowledge of That One Episode From Season 7 from my mind it's actually a really good example of what I mean. In any setting (that isn't 110% skeevy) in which "love spells" exist, they come with warnings if not outright taboos, because love compelled is love untrue. Which is a pretty way of saying "sex minus consent equals rape" bar goddamned none. Given that Sam was manipulated/coerced into that marriage, consummating it would have been rape. The fact that it was magical coercion is irrelevant: it was still coercion.

Now then.

If we were to ignore the maternal-filial nature of the Winchester brothers’ relationship and presume, for a moment, that they’re just brothers, you can’t ignore the fact that they were specifically and painstakingly raised with a chain-of-command power imbalance. All this still applies: you’ve either got Dean taking advantage of Sam’s hero worship and instilled instinct to go along with what Dean wants (and let’s not kid ourselves – he may argue, he may rebel, he may run away, but in the end he almost always comes back and gives in), or you’ve got “take care of Sammy” being perverted into the idea that if Sam wants a romantic/sexual relationship then Dean has to give him that. Either way it’s not healthy and not truly consensual even though they’re adults.

It's true that there's no threat of either of them bearing deformed young given they're both cismen, the likelihood of either of them entering a strategic marriage is slim to none (and Slim's out of town), and they're already outlaws who exist on the periphery of society and sustain themselves on breaking taboos (eg dabbling in various forms of magic, desecrating graves, stealing, lying, fraud, etc). With all that in mind, were they raised apart then I'd agree that Wincest would have no appreciable consent issues and would in fact make a lot of thematic sense, given the Gothic basis of the series.

But they were raised together. One raised the other. Their imbalanced power dynamic is part of the foundations of the show. Therefore there's no way Wincest can exist without problematic lack of true consent or without abusive elements.

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