Another way you could perhaps go at it would be to give a reason to one side to remain more quiet, while following the second character instead.
Lets take this as an example.
Steve saw Leia was waiting for him in the parking lot, where they agreed to meet. But she looked nervous.
"Hey Leia, everything good?" he waved to her.
Leia turned to me, nodded, and waited until I arrived at her side.
"So what was so urgent? I thought we weren't supposed to meet until Tuesday?"
Leia nodded, before leaning over and whispering in his ear. While Steve knew she was the cautious type, this felt like overkill. He listened until it dawned on him what she was saying.
"Wait, you want us to do what? Are you insane? You know what Greg would do if he caught wind of this?"
Leia grabbed Steve's ear and whispered something more, which caused Steve's expression to turn pale.
"R-right. I suppose you have a point there. But when-"
Before he could finish his question, he felt a note get placed in his hands, Leia gave him a wink, then quickly left the lot. Steve just look at her for a moment, before noticing something on a nearby pole. It was a security camera. Understanding now why she kept quiet, Steve quickly left the parking lot as well, deciding to take a look at the note later, when he would be in a more private setting.
But every other suggestion given so far feels like a pretty good one too. Each can give a different feel to the novel, so go with the one that feels right to your story! ^^