The Simpson's or The Simpsons - Possessive or Plural?

[Anonymous]

I am writing an invitation that says, "A Summer Shindig at The Simpson's". Do I leave the apostrophe or take it out? Does the apostrophe stay as the possessive meaning "The Simpson's house?" Or should I take it out because it is just a plural as "The Simpsons?" Or is it neither?

 

[Casiopea]

I am writing an invitation that says, "A Summer Shindig at The Simpson's". Do I leave the apostrophe or take it out? Does the apostrophe stay as the possessive meaning "The Simpson's house?" Or should I take it out because it is just a plural as "The Simpsons?" Or is it neither?

According to the official website , the word is spelled Simpsons, with a plural marker "-s": Mom, Dad, Bart, Lisa, and the baby (i.e. They) are The Simpsons, more than one Simpson; singular: Bart Simpson, Lisa Simpson, and so on, without the "-s".

Possessive form: The Simpsons' (house), with an apostrophe after the plural marker "-s".