I work in the same company as my partner - big company, big office. I initially was a little cautious as I never thought working in the same environment would be a good thing - plus I work for senior management and as Nicola said I always know what's happening or about to happen.
However, it's just establishing a "professional" boundary I suppose - he doesn't ask me questions which he knows I can't answer.
I don't feel any pressure cause we work together - our colleagues are happy, we are too, it doesn't stop me doing my job properly.
So far so good !!

Helen