If that was supposed to be a joke, Tony couldn't make himself laugh, only press his lips together and raise his eyebrows to make sure Pepper really thought that was a good place to go. Maybe she was trying to make a point. Tony really was trying to keep the mood light, though-- if he couldn't do that, he might as well leave. He definitely wasn't there to encourage Pepper's suicidal streak.
"You don't, Pepper," he said. "It's dangerous. It's dangerous for you, and it's dangerous for your kid, and it's dangerous for the people you want to protect the most." Maybe she needed him to say that because he hadn't apologized yet, but it felt so big. No apology could truly cover what he owed her, and Happy, and it certainly wasn't going to make anything better. "Let me fix this, okay?"