"let's be careful," Felipe had said then, out of the blue. 
"Of what?" I'd asked.
"Let's just be careful of what we say to each other for the next few hours," he'd gone on. "These are the times, when people get tired like this, that fights can happen. Let's just choose our words very carefully until we find a place to rest." 

Nothing had happened yet, but Felipe was floating the idea that there are, perhaps, moments when a couple must practice preemptive conflict resolution, arresting an argument before it can even begin. So this had become a code phrase of ours, a signpost to mind the gap and beware of falling rocks.