This troper does this all the time with her (gay) best friend. We've got the whole LikeAnOldMarriedCouple vibe going on, (and always have, prompting a lot of ShipperOnDeck action from our friends back in high school) and we totally use it for our own amusement. For April Fools Day, we got a reservation at the most swankified restaurant in town, and he proposed using one of my rings. When I accepted, the staff gave us a complimentary bottle of champagne. He and I just got back from a vacation in Germany, during which we pretended to be a married couple and, just to keep things interesting, kept insulting each other. He would say
"Ich leibe dich", to which I would repond "Fick dich!" I would call him a
"singe castré" and he would call me "déesse étonnant", and so on with Spanish, Italian, and Japanese. Suffice to say that the whole vacation could have been titled the ShipTease / FunWithForeignLanguages World Tour.