It's an extended metaphor, comparing a relationship to a dangerous race. Sometimes, a guy can't tell whether a woman wants to break up with him or not. He's trying to make the relationship as exciting as a race, but is afraid of crashing and burning due to a miscalculation. Especially in the beginning, a lot of relationships consist of tightrope walking and a fear of screwing up end everything.
It's an extended metaphor, comparing a relationship to a dangerous race. Sometimes, a guy can't tell whether a woman wants to break up with him or not. He's trying to make the relationship as exciting as a race, but is afraid of crashing and burning due to a miscalculation. Especially in the beginning, a lot of relationships consist of tightrope walking and a fear of screwing up end everything.