The loving looks begin outside the gate, jump to the jetbridge and snuggle themselves into coach seats in the Southwest Airlines courtship ritual.

Low-fare U.S. carrier Southwest likes to say it is the airline built on love, and thanks to an open seating policy where customers are free to chose their seats, many a romance has taken off with the purchase of an inexpensive ticket.

Over the years, the Dallas-based airline which calls the city's Love Field its home has received thousands of letters and scores of wedding invitations addressed to top executives from couples who met on one of the airline's flights.

"At times, we feel that we are the love brokers of the sky," said airline spokesman Ed Stewart.

A passenger on Southwest receives a boarding pass based on how early they check in for a flight and the pass will assign them to one of three boarding groups. Passengers board with their group and are free to choose any seat on the plane.

Southwest is the only major U.S. carrier with such a policy and all of its seats are coach.

That policy led to wedding bells for Beth and Derrick Zefo of Nashville, Tennessee. Beth saw Derrick as they were boarding a flight to Chicago, and thought he "was kind of cute."

"He was seated on the plane first and was sitting by the window. There were two empty seats next to him and I decided to ask him if I could sit there," Beth said.

The two shared a turkey sandwich and conversation on an 80-minute flight. They met at the airport in Chicago by chance on their return flight and later set up a date.

Their marriage resulted from a policy that allowed the outgoing Beth to sit next to the more reserved Derrick.

"Even for someone shy, if you sit next to someone who is open, it can make for an enjoyable flight," Derrick said.

(Agencies)