Hi Paddy, congrats on finding love in the lab! Your situation could get very complicated (if the worst happens and the relationship breaks down), it can also work well. I have no direct experience of this situation but I know of at least two couples who work well together within the same reseach group. Perhaps you could discuss potential problems with your girlfriend and work out how to maintain your professionalism and work output during working hours, without putting a dampener on your relationship. Good luck!