Not a physicist but I'd guess nothing would happen when the event horizons touch as the black holes themselves are point objects at the center of thoses spheres

Not a physicist but I'd guess nothing would happen when the event horizons touch as the black holes themselves are point objects at the center of thoses spheres. So neither's mass would be within the event horizon of the other. When the central point of the smaller black hole crossed the event horizon of the larger I guess they would merge. Just a slightly informed guess. Would love to know the answer from an expert.