The first thing I noticed was the woman's hand. It was resting in the bend of my husband's elbow with the effortless confidence of someone who believed she belonged there, her carefully manicured fingers brushing the expensive watch I had given him on our tenth anniversary.
The second thing I noticed was the small white reservation slip tucked beneath the transparent tag of his black carry-on.

It carried the name of a resort in Cancun and, directly underneath the reservation number, two words that might have been harmless anywhere else: Anniversary Package.
Then Ryan looked up and saw me standing in the open aircraft doorway. His foot stopped in the middle of a step, his suitcase tilted, and his sunglasses slipped from his fingers onto the jet bridge floor. The beautiful blonde woman beside him turned toward the sound, puzzled by the sudden break in his stride. I had never seen my husband look at me the way he did in that moment, as though I were not a person he had lived with for eleven years but an impossible event the universe had arranged for his particular punishment.
"Ryan," she whispered, pulling lightly on his arm, "why is that flight attendant staring at you?"
I smiled. My cheeks knew how to do it even when the rest of my face wanted to fall apart. Nine years as a flight attendant had taught me that the smile belonged to the uniform, not necessarily to the person wearing it. "Good afternoon," I said. "Welcome aboard. May I see your boarding passes?"
Ryan Carter had a hundred different expressions for difficult situations. I had seen his charming expression at charity dinners, his impatient expression when a subcontractor called during Sunday breakfast, and his wounded expression when he wanted me to apologize for something he had done. What I saw now was new. The color drained out of his face so quickly that even the woman beside him noticed. "Valerie?" he said, and my name sounded like it had caught on something sharp in his throat.
"Hello, Ryan."
The woman looked from him to me. She wore a red satin dress beneath a cream-colored travel jacket, gold hoops that caught the light, and heels designed for an airport lounge rather than a long walk between terminals. She was not the caricature of a mistress I might once have imagined. She looked poised, intelligent, and suddenly very uncertain. "You two know each other?" she asked.
Ryan opened his mouth. He shut it again. For years he had been able to talk his way around almost anything, particularly when the person listening was me. He seemed to be looking for a version of the truth that would satisfy both women without requiring him to surrender any of the life he had constructed between us. He did not find one before the elderly gentleman behind him cleared his throat.
"Some of us are trying to get to Mexico today," the gentleman observed, not unkindly.