In a situation when one person says something, and another one agrees with them, he/she might say "Me too". If you also agree with them, but don't want to be seen as boring (by saying "Me too" just like that second person) or stupid (by saying "Me too too") you might want to say "Me three".

The best answer to literally anything

When some female wrongly accuses a male of sexual harassment either for revenge, fun, attention or whatever and the man pulls a methree movement on her. You ( the female ( s) involved) , me and my lawyer .

The lonesome person who says "Me Too!" after someone already says it and instead says "Me Three!" which doesn't really make any sense.