Lewis's, Lewis', Lewises

I would say, “The Lewises, est. 2021.” The apostrophe makes it seem possessive, so omitting seems right, to me.

Hope that helps.

Assuming the family's last name is "Lewis" and you're asking for the plural of it, it would be "Lewises."

Lewis's is the possessive form of the singular name "Lewis"

Have you seen Lewis's new car? <<one Lewis owns the car

Lewis' is the possessive form of plural Lewises.

The Lewis' new house is great. <<multiple "Lewises" own the house

Long story short, you can rarely use an apostrophe to make something plural, and really never with a noun.

That all said, if you find "Lewises" to be undesirable as a plural, I know some folks with last names ending in -s that choose to write "The Lewis Family" rather than the plural.

If you are trying to say the house belonging to the Lewis family, then I would say The Lewises’. If you are saying the family was established in 2021, the Lewises

I’ve said Lewis in my head so many times while researching this Lewis now sounds weird to me. Is there a name of that feeling of a word seeming odd suddenly?

Ugh I'm trying to do this now. I married into a Lewis family and wanted to get a neon sign made. Explain why this common, simple name is being so extra.

If that is the last name, you would use "the Lewises" thats the standard plural. If you mean plural possessive then you would go for "Lewises'"

https://englishcrafter.com/lewis-possessive/