I wonder if anyone's been in this situation and what to do:

I head back to the States soon after traveling in South America for several months on a ticket I bought with miles. When I bought the ticket, I did a simple roundtrip LAX-CUZ. I'm now in Lima so I don't need the CUZ-LIM leg of the trip back. This isn't so much changing my entire ticket but just cutting off the short first leg of it. If I check in and print out my boarding pass for this first leg and just don't get on, will I get kicked off the second, international leg of the flight (LIM-LAX)? Or do I really need to pay the $150 to do it officially?

I know $150 isn't much in the grand scheme of things, but my last known paycheck arrives in April and I'm trying not to be wasteful.

and yes, if you do not board the first leg of your flight, the airline will not allow you to board the second leg. Having a boarding pass printed out means nothing..

Bummer. That's what I figured but at least I can feel better paying knowing there's really no alternative (except fly back to Cusco which, if I can get all my work done here in the next day or two, may be an option)

Thanks so much! I have to admit that I find all these rules and regulations to be confusing. Glad to have found a forum to learn from other people's experiences!