People shouldn't need to qualify their gender to others.
Mary sees Jake approaching multiple single stall bathrooms and needs to go at the same time Jake is.
Mary wants to know which bathroom Jake is going into.
Mary asks which bathroom Jake is going into directly instead of asking about gender, and Jake tells her.
Mary asks Jake what his gender is to determine which bathroom they will enter, and Jake says which one.
Jake appreciates Mary's courtesy and doesn't make Mary wait long.
Jake becomes mad at Mary for asking about their gender.