I complained about this a Christmas or two ago when I saw some Lifetime film with this scenario. The main character was a woman from Louisiana who was presently living in New York and the fake boyfriend was her best friend's brother. So when they went back to her hometown and her family asked how they met, they both looked like a deer in headlights. Just tell them the truth!
The thing that really got me was that they had to make plans for the flight, sit at the airport for an hour or two before the flight, be on the same flight for at least three hours (I was so annoyed I Googled how long