Stewart, who rocketed to fame playing Bella Swan in the Twilight films rushed through the terminal Thursday while holding hands with Cargile.
The Runaways actress is said to be "inseparable" from Cargile, as the duo recently got matching tattoos.
The Snow White and the Huntsman actress and Cargile have been spotted together in public many times, often garbed in grungy gear with baseball caps.
The Still Alice star leads the way in a dark blue sweater with blue jeans.
The On the Road star makes her feelings clear to paps on hand at the travel hub, which is always buzzing with celebrity arrivals and departures.