  We point out that when doubly-charged bileptons are pair produced at the LHC,
kinematics dictate that they are both almost at rest in the lab frame and
therefore their decays lead to final state muons in a characteristic X-shape
with only very tiny track curvature because of the high muon energies. Such
X-events have essentially no standard model background and provide a smoking
gun for the 331 model.
