Now that I think about it, my (white) ancestors have been enslaved by people with darker skin color, and they never enslaved people with a darker skin color. Does that mean I can call black people racist if they point out my skin color?

Yes. The word "slave" literally comes from "slavs"

Yes of course, and not just Irish or Slavic people. But how is that relevant to the question?

White people have been enslaved at various points in history.

Pahaha. YES!! What a historically ignorant question.

Here's a picture of an Arab man and his white slave, for starters: https://en.wikipedia.org/wiki/White_slavery#/media/File:Mecc...

Lookup Arab slave trade, and slavery in Ottoman Empire.

Yes, it just happened slightly longer ago. Romans took slaves from and performed genocide on european populations who were generally lighter skinned and the cultural attitude considered them uncivilized animals. Later on, one set of my ancestors had a habit of enslaving another set of my ancestors, however writing was something fairly novel to both of them so it wasn’t well recorded.

Slavery in many kinds is everywhere in human history, there aren’t many ways to divide up humanity so that any group hasnt been both victim and perpetrator at some point.

You don't have to go as far back as the Romans. The Barbary Pirates (from north Africa) took something like a million slaves from Europe over the 300 years that they terrorised European coastlines, mainly raiding the Mediterranean but sometimes coming as far north as Britain and even Iceland.

More information: https://www.historic-uk.com/HistoryUK/HistoryofEngland/Barba...

Note that Barbary slave raids weren't suppressed until the early 19th century, around the same time that the trans-Atlantic slave trade ended (emphasis on trade; slavery continued in the Americas for decades after the slave trade itself was ended). So slavery of white people was widespread for much of the time that whites were enslaving Africans. (And of course, Africans were enslaving each other for hundreds of years before Europeans showed up and continued to do it after Europeans stopped.)

The only thing more absurd than pretending slavery never happened is pretending that Europeans were the only people who ever practiced it.

No, because the new dogmatic definition of racism and sexism excludes the possibility of white people and men as a gender ever being discriminated against at.

Also known as “There’s no such thing as reverse racism!”, which as a premise to fight racism (different treatment based on skin-colour) starts off by dividing people into different skin-colours, so that they can be treated differently (and the equivalent mental exercise for sexism/gender).

It would be hilarious if it wasn’t for the fact that it’s being done seriously and gaining momentum.