"The mouth" is an English equivalent of the French words "la bouche." Specifically, the feminine singular definite article "la" means "the." The feminine noun "bouche" means "mouth." The...
It literally means: "The party in your mouth".
La means "the" La Rosa would mean "the rose."
Basically 'ooh la la' is an exclamation of surprise, with very strong sexual connotations.
the soup