  Exoplanetary systems are found not only among single stars, but also binaries
of widely varying parameters. Binaries with separations of 100--1000 au are
prevalent in the Solar neighborhood; at these separations planet formation
around a binary member may largely proceed as if around a single star. During
the early dynamical evolution of a planetary system, planet--planet scattering
can eject planets from a star's grasp. In a binary, the motion of a planet
ejected from one star has effectively entered a restricted three-body system
consisting of itself and the two stars, and the equations of motion of the
three body problem will apply as long as the ejected planet remains far from
the remaining planets. Depending on its energy, escape from the binary as a
whole may be impossible or delayed until the three-body approximation breaks
down, and further close interactions with its planetary siblings boost its
energy when it passes close to its parent star. Until then this planet may be
able to transition from the space around one star to the other, and chaotically
`bounce' back and forth. In this paper we directly simulate scattering
planetary systems that are around one member of a circular binary, and quantify
the frequency of bouncing in scattered planets. We find that a great majority
(70 to 85 per cent) of ejected planets will pass at least once through the
space of it's host's binary companion, and depending on the binary parameters
about 45 to 75 per cent will begin bouncing. The time spent bouncing is roughly
log-normally distributed with a peak at about $10^4$ years, with only a small
percentage bouncing for more than a Myr. This process may perturb and possibly
incite instability among existing planets around the companion star. In rare
cases, the presence of multiple planets orbiting both stars may cause
post-bouncing capture or planetary swapping.
