Currently, the docs for Path.relative_to read

    PurePath.relative_to(*other)
    Compute a version of this path relative to the path represented by other. If it’s impossible, ValueError is raised: (examples follow)

It's a bit confusing why other is a star-args, especially as no example actually passes more than one argument to relative_to.

The docstring is a tiny bit clearer:

    Return the relative path to another path identified by the passed
    arguments.  If the operation is not possible (because this is not
    a subpath of the other path), raise ValueError.

Effectively, a Path is constructed from all *other args and used as base for the computation of the relative path.  It looks a bit like a misfeature to me, but at least it could be better documented (e.g. by adding `Path("/tmp/foo/bar").relative_to("/tmp", "foo") == Path("bar")` as example in the docs).