Is this considered multi-racial?

Multi racial between white woman and black man is wrong .

why is this under the sex category lmao

Can't believe you ask this.
White is white.
Other is other.
Hopefully she's at least from the Ukraine.
Either way, you're white.
Multicultural.
But not mixed race.

Purely sociologically speaking, that's multi-ethnic and not multi-racial.

Race is usually based on physical differences seen as distinct by society (hint, its not real. We're all humans. Since its based on perceptions, anybody of European origin is usually just seen as white). In terms of data collection, there are five races which would be African/Black, White, Native American (including central Americas and Alaskan Natives), Asian, and Pacific Islanders. Due to weird old laws and policies, Middle Eastern and North African people were lumped into either "white" or "African" but people are lobbying for them to get their own official category soon. Sources below.

An Ethnicity is the fact or state of belonging to a social group that has a common national or cultural tradition. Germanic and Russian people may appear similarly, but they have different cultural traditions. Thus you would be multi-ethnic.

Sources:
https://www.livescience.com/33903-difference-race-ethnicity.html
https://www.census.gov/topics/population/race/about.html
https://www.usatoday.com/story/news/politics/2016/09/30/white-house-wants-add-new-racial-category-middle-eastern-people/91322064/

From what I know Slavic and Germanic people have common ancestry at least the Slavic people in Eastern Europe do and parts of Russia closer to Europe. I would say yes and no it depends I could be wrong.

You could say that person is multinational.