The way he stated this wasn't the best, but I will say this much: There's a reason that most people who could be considered experts in such things advocate avoiding romantic relationships with coworkers. I don't think there's any need to go so far as to make single-sex labs since adults should have the sense to either avoid letting the relationship get un professional or request a transfer if it is headed that way, but there's a lot to be said for avoiding romantic entanglements in the workplace, be that a lab or an office or a server room.
I once had to request a transfer to another work area because a romantic relationship was budding with one of my coworkers. Another time I made a go of it with a coworker without requesting a transfer. I've been there, and trust me. It's better not to work in the same area as your SO.