By being honest with her

"Miranda, honey, I can't lie to you," you tell her as you lean into her so that only the two of you can hear the conversation you're about to have with her, "there's a pretty good chance you're going to wind up pregnant with my kid."

"SHIT..." she moans under her breath, wanting to be mad, but forcing a smile as you look in her eyes and kiss her as you settle in for the rest of the flight.

"Let's not worry about this right now Miranda," you tell her as she lays her head on your shoulder and sighs to herself, her mind clearly heavy with all the thoughts of what a potential pregnancy could do to her career.

"Just promise me you'll stay with me and I'll be fine John," she whispers to you as she starts to let herself relax, clinging to your arm as she starts to get comfortable.

"I'll always be here for you Miranda, you have my word," you tell her as she rests her head on your shoulder again and starts to drift off as you kiss her forehead and wrap your arm around her, "whatever the future brings, we'll get through it together."

You had barely gotten the last part of that sentence out when you, too, started to drift off to sleep, the rest of the flight passing as both of you caught a nap and dreamed about the future together.