Quoted from TigerLaw:Parisian, for my wife anyway. Not sure how my son would be catagorized, he travels on a French passport. We are somewhat wondering how we will get him back into the states next week. We don't have an esta for him to travel into the US although he is a duel citizen with France and the US...I'm not sure how we will convince the ticketing person at the airport of that. Could be an interesting morning for us...
Free bump for the OP.
Good luck with the boarding. If I'm not mistaken, he can't get an esta since he's American. So I see your predicament. Hope all goes well at the airport. Airlines sometimes don't show that much flexibility. Canada has recently introduced the eta process for visa exempt passport holders. Someone who is dual (e.g. Canadian citizen and also visa exempt country citizen) can't get an eta and needs to have a Canadian passport to fly to Canada. We're seeing boarding refusals on an immigration forum because people aren't that familiar with the new rules yet. Hope it works out for you.
Also bump for the OP because someone should buy this.