Yeah it's definitely and iffy balance. It's just a matter of when pursuing your own interests becomes a threat to the other person's self-esteem. People inherently feel a need to belong and feel a sense of increased self-esteem, among other things, so says social psychology. So your story is an example of how two gamers can hurt each other in the same way a gamer and non-gamer can. Thanks for sharing your story, I never really thought of this aspect of whether or not the gamers are playing the same game.
That's the only thing that causes a little rockyness for my fiancee and I.
I started FFXI years before I met her. I started WoW before her too. So in both games, whenever we played, I was always ahead and she was always playing catchup.
We were both really looking forward to FFXIV so that we could start together on equal footing and grow together. It's why I'm not a high level; she doesn't get home till 11 PM - midnight and I need to be at work at 10 AM, so we don't get to play during the week. We only play during the weekend, and the weekends can be busy so sometimes we don't get to play during that time either. Either way, I don't want to play alone and get ahead of her and leave her behind again.
That's one thing I really don't like about XIV compared to XI or WoW; on WoW, your characters are separate. On FFXI, your jobs are all separate (Merits apply across all jobs, but other than that, they are) so I could always set aside "this character" or "these jobs" to play with her and play on my own separately; I can't play FFXIV without her without affecting my physical level. I wish I could temporarily turn off my physical level and play another class or two, but I can't.
At any rate, she has said that if she ends up not liking XIV, she's going back to WoW, and I've said that I am definitely not going back to WoW for Cataclysm, so we would be playing different games if that happened.
For the brief period that she was playing WoW and I was playing FFXI, it kinda sucked. I mean, we both had played each game so we both knew each other's game; she simply didn't have the time for XI and I was bored of WoW.
So I have to say that a gamer couple that plays two games is not as bad as a gamer/non-gamer, but it's maybe like living with someone who roots for a different football team in the same division.