Sometimes you might make a joke that seems harmless to you, but can be seen as offensive by other people. The right thing to do would be to apologize and refrain from joking about it any further. Joking about it even more and trying to defend it isn’t right… The thing is… people were offended whether or not it was intended to be a joke.
It’s also not right to send someone offensive messages regarding the joke they made. Attacking them on every weak statement won’t get anything anywhere, it’s just going to get both sides frustrated.
There’s no reason to fight about this!!