Viewed 3 lights in a line and another single light fly in formation over Puget sound from South to north

My friend and I sat on his back porch in recliners chairs in the Fremont neighborhood of Seattle at 2:30 am sun jul 31st 2022. While conversing I said something about not believing in god (coincidence) and just then, viewed 3 lights in a line and another single light all fly in formation over Puget sound from South to north. I heard one jet but my friend did not. We had seen multiple planes in the sky over Seattle around that time, however.
It appeared like they were in the shape of a triangle pointed in the direction of their movement. The 3 lights on the west back corner of the triangle and the single light on the east back corner of the triangle. My friend asked me if I saw that and I confirmed I saw it as well. My hypothesis is that it is a Boeing test flight done at night to reduce observability of the experiment. The 3 lights could be the observer craft recording multiple angles of the single light experiment.