My employers security team has even caught on once or twice but I just say yeah I'm vacationing since my stays have usually been along the lines of 45-60 days or so at a time in a given country.
I still have and maintain my home address in the US, pay the rent and everything there, and I do return usually for a month or two at a time. Most of my friends do this as well or have a situation setup where they use their parents address and stay with their parents when back in the US for chunks of time.