I've done this several times. I have to exit/enter Australia with my Aussie passport, and same for Canada with my Canadian passport. When I get to the US I usually just use my Aussie passport, but once my ESTA had lapsed, so I just pulled out the Canadian passport and presto, I'm in. The guy d...

I had an issue as Velocity Gold member flying LAX to SYD on a flight booked through Virgin Australia but operated by Delta. Went to the Delta lounge and they wouldn't let me in because the flight was ticketed by Virgin, told me to use the Virgin lounge, which was Etihad. Went to Etihad and they...

I fly a lot but not always on Singapore Air - had the same question. Now that I'm platinum, thinking of starting to use my Krisflyer number to work toward Star Alliance. I guess the downside is not getting the free Economy X upgrades.