Saw two slow moving black triangles high up in the sky.

My fiancée and I were outside our house stargazing when a set of lights directly above us caught our attention. They were faint and small leading me to believe that they were high up in the sky. Once our eyes were able to focus on them, we could both make out two triangle shaped objects. One had three lights on each end and the other had at least one. They flew very close to one another and were completely silent, flying slowly to the north until they faded from view.