Marian pops the question. No, not that question.
Here
John's face softened with affection, and Marian's eyes swiftly noticed this.
"On another note, John, I have to ask you a question."
John nodded, noticing a newspaper near the coffee press and snatching it up to flip through it. "By all means."
"When are you and Sherlock getting together?"
John paused, looking up at her. She was completely serious, he realized with some surprise, and he found himself quickly saying, "Wait, what? What on earth are you talking about?"
"It wasn't a hard question, John."
Bewildered, he stared at her. "Why would you ask that?"
"...Well, he brought you here."
Prompt was from Sailasiri Culnamo, and it was: swift