Just because I am a native English speaker and I am living in a place 
where learning the English language is a hot commodity doesn't mean that
 I have any desire to do meet ups with people to help them improve their
 English.  The catch is always "and I can help you improve your 
Spanish!" but I get enough of that already.  Not every moment of my day 
has to be spent learning Spanish, that's not the reason I am here (but I
 think people think that I am here primarily to learn Spanish).  I'm 
frusterated at how many people (relatives and friends of the family) ask
 me if I want to meet up to do a language exchange.  If I said yes to 
all of them, I would be busy all day every day with helping people 
improve their English.  The only way I would do it is if I were getting 
paid.  My time is valuable.  I want to choose how I spend my day, even 
if it means having a siesta and watching a movie.  It's my experience 
and it doesn't have to revolve around learning a language.  I feel 
guilty when I don't want to do language exchanges, like people perceive 
it as a positive thing and by saying no I am turning down an experience.
  Too bad, it's not the experience I want to have.
The only exchange I am doing now is an hour of English a week for free yoga classes in return. I think its a fair trade, especially since yoga tends to be expensive and I like doing it.
The only exchange I am doing now is an hour of English a week for free yoga classes in return. I think its a fair trade, especially since yoga tends to be expensive and I like doing it.