One thing Natasha had always been good at was putting on the appearance of essentially being an open book, even if she actually wasn't. There were moments of vulnerability, of genuine emotion, but overall she was adept at hiding behind snarkiness and actually showing kindness when it was needed. For Tony, she was willing to put him at ease however she needed to.
More or less.
"It just so happens that there's a decent spot half a mile from here." The charming smile earned him an answering smirk as she started them down the street. "I do know that. Making Pepper CEO was a big turn on for you," she said dryly, glancing over at him in amusement. "Are you planning on building a tower here?"