Had to help a manager friend recently with a sticky subject - romance in the workplace.
Most of you know the drill. Two lovers come together, find fulfillment and... wait, that's the romance novel version.
Let's give a cleaner version. Two employees in the same work group are hooking up. They enjoy each others company and aren't afraid to show the rest of the world at work. They dig each other. What's wrong with that?
There's nothing wrong with that. Other than humans being completely miserable at times and paranoid basically all the time. That means if you've got members of the same department/team in your workplace who are together, it's bound to stir some stuff up.
I'm giving you the GlenGarry notes here. You don't need a policy or a love contract.
Here's all you need to do - coach them that they should manage their relationship in a way during work that if a 3rd party came to visit the office, there's no chance that the 3rd party could spend 2 hours with and around the team and guess that the love couple in question were buying sheets together after work.
That's it - can an outside visitor guess? If not, you're (or they) are good to go. If an outsider could guess, you're not good to go. Fix it or one of you might have to go.
And of course, 3rd parties coming in to spend time with the team aren't generally available, so manager observation rules the day in this area, with feedback from those around them.
All kinds of couples manage this type of relationship at work in a great way - there's no reason to hide from the conversation.
Coach them up, Scotty.