In Newtonian gravity you need at least three bodies to arrange an ejection: two of them start orbiting more tightly, to counterbalance the third one flying out

In Newtonian gravity you need at least three bodies to arrange an ejection: two of them start orbiting more tightly, to counterbalance the third one flying out to infinity. (IIRC this happens a lot in globular clusters, and simulations like yours.) With just two bodies you get only Newton's solutions, the conic sections.