A few things to note here:

1) `success?` should not have side effects. It should just be telling you whether something was a success, not actually making the success come about (or not come about!) by doing something like creating an `Expense`.

2) If the `create` on [line 29](https://github.com/bignerdranch/ShindigSheriff/pull/89/files#diff-c0dc3d52f69f21b9f3d7514142e0affbR29) fails, you're going to essentially be calling `false.valid?` which is wrong.

If you want to quack like an `ActiveRecord`, it would be as simple as renaming this method to `save`.