The present research examines whether romantically involved individuals process behavioral information of attractive alternatives in a biased manner. When presented with behavioral information of an attractive mate, in Study 1 involved (vs. uninvolved) participants tended to recall fewer positive behaviors of an attractive alternative. Study 2 demonstrated that involved participants recalled more negative behaviors, and also evaluated these behaviors more negatively, compared to uninvolved participants. Study 3 demonstrated that romantically involved participants recalled more negative (but also neutral) behaviors when it concerned behaviors displayed by an attractive alternative as compared to a same‐sex other. These findings provide initial evidence for biased processing of behavioral information of an alternative mate, which may serve an important relationship protection function.