You tell Siri “Call my honey bunches of oats!” and she says what?

You can make Siri understand any kind of relation or pet name you like.

mother in law
father in law
sister in law
step mom
step dad
first cousin
honey bun
boo boo
baby cakes
etc

Here is how you can make her understand:

1. In Contacts find your contact info (the same one that is set in Settings > General > Siri > My Info) and add a custom label.
2. Call the custom label “honey bunches of oats”. Now you have a new field called “honey bunches of oats” which you can assign a value to.
3. In the field value type in the name of the person who you refer to as “honey bunches of oats”.

i.e
In your contacts it should look like this:

Most Interesting Man In The World: John Appleseed

You: Tell Most Interesting Man In The World Whats up!

Siri: Here is your message to John Appleseed

Note: this does not work with google sync or exchange sync since they both use the same technology “exchange sync” which does not support custom fields. But even if you do use those services you can still add an iCloud address book with a single contact.  See this post for more info: http://tingalin.com/2011/10/15/siri-cant-remember-who-your-mom-or-dad-is/