Sexuality norms
The sexuality norms of this society are generally both homophobic and heteronormative. Despite this, there are multiple high-profile queer relationships which are not widely criticized.
This is due to the fact that they are relationships mandated by contract, which are automatically heterosexual. Not only were the template relationships heterosexual, contractual gender is considered in contractual relationships over actual gender.
However, this does not spread to two people with opposing contractual genders whose relationship is not mandated by contract. The contractual gender is only considered if the relationship is mandated by contract.
Of course, if one or both parties do not have a contractual gender, contracts are still not considered.