She looks flustered

You see Lily sitting upright, legs pressed firmly together. Finally she turns to face you, and you can see she's biting her bottom lip. Her cheeks are red, and her chest is rising and falling rapidly with heavy breaths. You worry she's holding in something difficult, some anger or condemnation.

Then you see the look in her eyes, and her appearance transforms as you see her in a whole new light. Her gaze is wide-eyed and intense, but not hostile. She's not red with anger, she's flush with arousal. Her legs are clenched because she's rubbing her thighs together to stimulate herself. Your fiancee is all hot and bothered, and you think you know why.

"Lily, did you get wet thinking about me fucking the flight attendant?" you ask, your trepidation melting into excitement.

Lily releases her bottom lip from between her teeth as she wiggles in her seat, then gives you a little shrug.

"Did you do it?" she asks breathlessly, her voice barely audible.

"In the bathroom, fast and hard," you reply.

It occurs to you that as amazing as your sex life with Lily is, "fast and hard" could never really describe it. And the thought of finally getting to experience that floods you with a fresh wave of euphoria.

Meanwhile, Lily nods approvingly, and you feel the rest of your worry dissipate. Then she leans in close so she can speak to you without being overheard.

"I did something too, like you said I should. With our neighbor," she whispers conspiratorially, gesturing with a slight nod of her head to the man sitting on her far side.

"I couldn't take him inside me, but I sat in his lap and we humped until he came. Fuck, it was so hot, I wish you could have seen it," Lily sighs.

You realize you can still smell the unmistakable scent of sex hanging about Lily. You don't respond right away, as her confession caught you off guard. Thinking about it is exciting and frightening and arousing all at once.

After a long pause, you realize Lily is looking at you intently, silently, looking for your approval. You pull her in close and give her a kiss on the forehead.

"It does sound hot," you agree. "If you tell me all about it, I'll tell you what happened to me in the bathroom."

Lily agrees gleefully, and the two of you swap stories. As Lily shares hers, you try to visualize what she experienced, and imagine all the ways it might have been different for her to fool around with someone new. Your chest aches with an insuppressible fear that your partner might come to enjoy sex with someone else more than sex with you. But you do your best to swallow that fear and enjoy the raw sexual excitement of what just happened. Once story-time is over, the two of you embrace and let the hum of the airplane engines lull you to sleep.