After an affair that cost us our jobs and marriages we have been together a few years still work together. The rough times have passed, we still work together for another company but there are still more tears than laughter. Have a chance at another job. It may eventually mean an end to our relationship. Do I take the job?
Taking the new job may actually help strengthen your relationship. It can't be easy working and living with someone. It sounds like you've both been through some very rough patches and you're still together. If there are still more tears than laughter after changing your job then it could be time to move on!
Good luck in whatever you decide.
If you really want the new job, go for it. Put the relationship to one side - if it wasn't an issue, would you want to go for the new job? If your relationship is strong enough, working apart will either strengthen it or make little difference. If it comes to an end simply because you have changed your job, then it wouldn't have lasted anyway.