I read in a forum people use '2 different passports' from 2 different countries. Use one passport while entering one country and use other while coming back. It's like:

Going to Nepal
Check in – Airline at US—Show my Nepali passport
Arriving immigration at KTM – Show my Nepali passport

Return flight
Checked in airline – Use my US passport
Departing immigration at Nepal: Use Nepali passport
Arriving immigration at US: Use my US passport

Does anyone know if it work for Nepal and US too??