I Get No Kick from Champagne

Or did you mean a real song, like the Camptown Ladies?

Why Black Holes Slow Down

Two black holes that are close enough will mutually orbit and eventually spiral inward toward each other, sending off ever-stronger gravitational waves (ripples in spacetime), until they collide and merge into a larger black hole. If the gravitational waves radiate mostly in one direction at the time of the merger, they “kick” the new black hole in the opposite direction. But some simulations have shown an “anti-kick” following the initial kick–the new black hole shoots away but soon slows down. Researchers haven’t had a clear physical explanation for the anti-kick.