My girlfriend and I have been together for about 9 months. I'm a pretty big soccer fan and she has taken up more of an interest in the sport since we've been together. We generally go to a local bar to eat breakfast and watch the English games in the morning on the weekends. A good friend of mine invited me to fly out to Philly and stay with him at his sister's place and drive up to NYC and watch the US-Argentina soccer match. I said that my girlfriend would very much like to go and he replied that he didn't want it to be a third wheel situation. I completely understood his perspective because I wouldn't want to be the third wheel either. I told my girlfriend the situation and that I really wanted to go, despite her not being invited. We argued all morning about it and she is convinced that by me going I am screwing her over. She's pretty much given me an ultimatum by saying that she can't imagine being with a boyfriend that would do this to her. "You're crushing my heart". How would your girlfriend react if you did something without her that she also really wanted to do?