2 jets chasing 1 triangular shaped aircraft.

Two gray fighter jets were chasing a dark gray or black triangular shaped craft headed west. I’m unsure the elevation they were at but looked to be about 1.00” long. I would guess they were 5000-8000’. They were doing slalom like maneuvers which is what caught my attention. They were moving so fast it caught me so off guard I didn’t even notice the black triangular aircraft at first. The triangular craft was seemingly just moving, if that makes sense. As in, there wasn’t the expected movement like the jets. Almost as if I was blinking very quickly as it would move, but I wasn’t blinking. It definitely seemed like the craft was easily outmaneuvering the two jets. Unfortunately I couldn’t react fast enough to get pics or video.