After reading several bloggers respond to Fned's post on multi-lingual couples I decided to share my story...
I met Mystery Guest in November 2005 at the English Tables in Caen. They were run every Monday night at the Irish pub by the TAs at the university to give the students a more open and comfortable environment to converse in English. So Mystery Guest and I started talking and within the first 2 or 3 sentences I could have sworn he was American so I asked where he was from (good thing I didn't ask "where in the States are you from"!!) When he replied Normandy I was surprised to say the least and decided that he must have spent extensive time in the States. He said 2 weeks but I heard 2 years because with his level 2 weeks was just not possible!
Anyway by that point I was starting my 3rd year in Caen and felt very comfortable speaking in French to collegues, friends, the bakerlady - you name it. On our first date we were speaking English and mentioned that we could speak French and English, knowing full well that I didn't start speaking French with him early on it would be difficult later.
We didn't start speaking French right away, for some reason a few months later I became petrified of speaking French to him, or having him hear me speak French. I'm still not exactly sure why, maybe because his English was just too natural or because I didn't want him hearing my accent or mistakes.. In any case we spoke 100% English for the first 8 months or so.
It wasn't until the first summer that I spent a lot of time out at his parent's house, with his family and his friends that I started to loosen up. There was just no way out - they didn't speak English and I was realizing how stupid it was to be afraid or embarrassed. I started to get more used to having him hear me speak French - yet wouldn't speak directly to him.
Now things have changed. We probably speak a majority of English at home but because our comprehension of eachother's languages is at the same level (and probably our expression I would think) when we're tired or lazy we can have a bilingual conversation and it doesn't seem odd or unnatural. I still have an accent but apparently its getting fainter and there are very few situations where I feel uncomfortable expressing myself in French (probably the same that I would in English - anything to do with vocabulary I'm not familiar with.)
I'd hesitated to put a percentage up but depending on the day it is 60% English / 40% French between us, or 70%/30% - not really sure. But the good thing is that both of us are very comfortable with the language that the other speaks. This is such a relief, not only between us but also between our families. I can be with his family and not feel hindered or uncomfortable (his mom said once, I don't see you as American anymore, yeah you still have a bit of an accent but you're just Karina. I thought that was really cute.) And when Mystery Guest came to the States for Christmas he was able to hold his own no problem ;-) Even playing Taboo!
I think the cutest thing is that my mom has started taking some beginner French classes :-) When I told this to his mom she got all wide-eyed and said that she'd better start with some English again! ;-)