If your wife says that she wants to reach a certain milestone in a video game before you, it is not an invitation to friendly competition, it is an ultimatum that you must not reach that point before her.
This was the first major mistake I made in our marriage. We got a Wii with Wii Fit as a wedding gift from our coworkers and my wife loved it. She was really good, particularly at the heading soccer balls game. She had become so good that she had knocked my scores off of the top ten scoreboard in the game. She had even come within one or two balls of a perfect score.
During a break from playing she said that she wanted to be the first one to get a perfect score on the game. I told her that I would beat her to it and she said that I had better not.
Now, I did not really think I would get a perfect score before her, but I took her statement as a challenge and started to focus on getting better. I had gotten a couple scores back in the top ten, but still had not come close to getting perfect. Then I did, on my last try before her turn. I was laughing, she was steaming mad.
She was not trying to get me to compete with her, she was telling me that she wanted to get the perfect score first. Lesson learned.