I want you to think about how jokes like this might feel to a transgender woman. If you really can't come up with anything on your own then I'll spell it out for you
It's transphobic because the joke is "Haha, you thought that was a lady but the person had a beard, so they're a dude!"
Trans women have to deal with facial hair. Trans women get murdered by dudes who were "tricked" by them into "thinking" they're women. This joke is literally as bog-standard transphobic as it gets.
Trans women have to deal with facial hair. Trans women get murdered by dudes who were "tricked" by them into "thinking" they're women. This joke is literally as bog-standard transphobic as it gets.
-A trans woman