What does "First at home." mean in English for Spanish?

In English for Spanish, "First at home." means:

Primero en casa.

Listen to "First at home.": (If you have an HTML5 enabled browser, you can listen to the native audio below)

This is a phrase that is used in the GamesForLanguage English for Spanish Language Game in the following scenes:

• English for Spanish 3, Level 1, Scene 3
• English for Spanish 3, Level 1, Scene 5
• English for Spanish 2, Level 1, Scene 1