Seriously, I used to be the "blue haired girl" at my old job. The reason I reacted is because gay "jokes" is making fun of me, my friends and a lot of people who's had to deal with this kinda shit for far longer than anyone can stand.
TL;DR If the "joke" makes fun of a group of people is not funny, it's offensive.
TL;DR If the "joke" makes fun of a group of people is not funny, it's offensive.