If person A is not gay, but person B calls person A gay while knowing that person A isn’t gay, what is this type of discrimination called?
I used to call it “pseudodiscrimination”, but I’m not sure if that word exists for something else. What is the word I need?
Try pigeonhole, defined by Merriam Webster as
To unfairly think of or describe (someone or something) as belonging to a particular group, having only a particular skill, etc.
Also see its definition by Cambridge dictionary : pigeonhole
to put someone or something into a group or type, often unfairly.