Consent is not a magic spell that obviates every potential moral problem with a sexual act. It's a necessary but not sufficient aspect of sexual morality. I don't think anybody is arguing that it's somehow less objectionable to cheat on a partner you've ostensibly promised not to; rather, the principle on which people operate is that carrying on multiple sexual relationships concurrently is objectionable regardless of how the people involved feel about it.
And where exactly does this principle come from that makes it any more legitimate than the principle of accepting that 1) it is possible to love more than one person at a time and 2) that consenting adults can do what they wish in the privacy of the bedroom?
I mean, from (the easiest, most well-popularized version of) secular liberal first principles it's hard to come to this conclusion through any route that doesn't rely heavily on disgust reactions, but if one presupposes (as I do) that the purpose of human sexuality is expression in mutual reflection and mutual gift (bracketing out for a moment the question of to what extent we should feel bound by the other, more obvious biological 'purpose' of sexuality, a question on which I'm certainly less than impeccably ~traditional~ myself), then it strikes me as fairly reasonable to conclude from that presupposition that that reflection becomes distorted if more than two mirrors are facing each other.
I don't expect you (or most other posters, including many of the ones I like best) to agree with that, but I hope it makes some degree of sense anyway.
I don't think anybody is actually denying that it's possible to love more than one person at a time.
You don't say!
You're perfectly free to have an understanding of morality that starts and stops at not measurably harming third parties if you wish, but I'd suggest you make some effort to understand why many people don't consider that sufficient. Reducing any attempt to reintroduce aesthetic and (in the broadest sense) liturgical sensibilities into a type of conversation that too many people on what passes for 'the left' these days would rather have solely on the level of health, harm, and safety to 'just because' without going through even a pro forma step of asking what those sensibilities are is in unbelievably poor taste and is an unacceptably bloodless and frivolous way of conducting moral arguments.
Anyway, now that the argument over the morality of same-sex relationships qua same-sex relationships has (as an animating social issue) been more or less resolved for the better in the parts of country and types of online spaces I frequent, I get to settle into the self-satisfaction of being able to see the phrase 'consenting adults' and immediately know that it's being used as, essentially, the sexual morality equivalent of 'but it's my First Amendment right!'.
Yeah, sorry, but this makes no sense to me. I don't see any reason to call something "immoral" if it's not hurting anyone. You can make fun of that argument all you want, but I have yet to see a legitimate rebuttal to it.
As a side note, it's sad how Smilo has gone from a generic nice guy to one of the bottom five posters on this site. Trump really brings out the worst in people I guess.
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