Why is it so impossible to understand when people ask you to use certain language to describe their lives, experiences, gender?

I was on the phone, going through my personal details. We came to the section about my relationship status, and the man asked if I was married, single, divorced, etc. I hesitated, saying: “I’m dating someone, does that count?”, and he answered, “don’t worry about your boyfriend, we’ll put you down as single for the purposes of this form.”

His use of the word ‘boyfriend’ registered with me. I could have been gay or bi-sexual and dating a woman. He assumed I was straight, because he assumed heterosexuality as the default position. That reminded me of a panel discussion on gender I took part in last year.