My kids can't decide if I speak Spanish or not, despite the fact that they occasionally hear me explaining things in Spanish to the students who need it. It obviously doesn't have much of an effect on their working memories... Here's a typical conversation:
Student 1: "Natalie, que ...... [insert roll of mostly-intelligible Spanish] .....?"
Student 1, realizing he just wasted a lot of breath: "Pero, ¿hablas español, o no?" But you don't speak Spanish?
Student 1: "Pero, ¿me entiendes?" But do you understand what I´m saying?
(Student 1 is understandably uncertain.)
Student 2: "Que no habla español, coño." Ya lo sabes! Dude, she doesn't speak Spanish. Duh!
Me: "Exactly. Gracias, Roberto. Ya lo ves." Thanks. That's about the size of it.
Oh, the life I live... :)