The most natural sexuality is not heterosexuality, but heteroflexibility. Bonobos know this, their society is heteronormative but indifferent to homosexual behavior instead of hostile to it, the whole social structure revolves around straight sex but gay sex is still given a mainstream role as a friendly release of tension between heterosexual rivals. That's the kind of hetereonormativity that belongs in human society. Having heteronormativity that's hostile to homosexual behavior, rather than indifferent, is an aberration against nature because it constrains us only to our most preferred sexual behavior and leaves unsatisfied our natural drive to sometimes accept the second choice.