Heteronormativity is a concept interpreted in many different ways, but it mainly concerns the idea that society accepts and even celebrates certain kinds of sex and relationships while shaming other types of sex. Heteronormativity upholds certain kinds of sex as the norm.
Heteronormativity includes the idea that heterosexuality is normal and superior to other sexualities – but it doesn’t stop there. It also includes the idea that we should only have sex for reproductive purposes in a romantic, committed relationship. It also includes shaming sex workers, people who enjoy BDSM, polyamorous people, and people who wish not to get married or have long term monogamous romantic and sexualities relationships.
An everyday example of heteronormativity is school application forms having a section for the father’s details and another for the mother’s details. What if the prospective student has one parent? Parents of the same gender? Polyamorous parents? The seemingly harmless assumption results in marginalising families that don’t fit the norm.
Another example is if a man announces his engagement, and an acquaintance assumes his future spouse is a woman without having actually been told the man’s sexual orientation. – SF