I am suggesting a linguistic difference. If I declare "its a nice day," I'm taking a public stand upon myself as one-who-is-enjoying-the-weather, at once naming and disclosing/describing my being-before-the-elements. The truth of the nice day is neither essentialist nor relative, but a potentiality for coming-to-be in different worlds of cultural meaning. (We are always bound to our cultural world but this binding becomes tenuous on the few occasions when we adopt a purely theoretical/Cartesian subjectivity and for example describe a nice day by noting the geometric shape and position of the clouds, the angle of the sun and the particular hue of the surrounding colours.)
A heterosexual act, by contrast, ought not to involve a public stand as a heterosexual subject because sexualities do not meaningfully exist as cultural subjective identities but are constructed by social performativity in such a way that they only exist in their performance. Linguistically, homosexuality performs itself in its utterance, in the same way that answering I do at a marriage ceremony performs an act of marriage but unlike marriage it does not reveal a subject because sexualities are empty of subjective content. They are acts not identities.