Adult perpetration rates of sexual aggression (defined as: acts in which an individual uses verbal pressure, arousal techniques, coercion, alcohol or drugs, or force to have sexual contact with someone against his or her will) were compared among an MTurk sample of 341 Baby Boom-GenX men, 356 Baby Boom-GenX women, 465 Millennial men, and 309 Millennial women (Mdn age = 30). Logistic regression analyses revealed a significant generation by gender interaction effect for use of six behaviors: pressured or forced sexual outcomes (PFSOs) without sexual intercourse; PFSOs with sexual intercourse, any tactic of post-refusal sexual persistence (PRSP), and PRSP tactic sets related to arousal, emotional coercion, and intoxication. No interaction effect was found for the PRSP tactic set of physical force. Follow-up analyses revealed that for four measures (any PRSP, PRSP sets for arousal, emotional coercion, and intoxication), Baby Boom-GenX men had significantly higher rates of sexual aggression than same-generation women, but Millennial men and women had statistically similar rates. This outcome replicated a pattern termed the Millennial Shift which we detected in earlier work. We suggest that the Millennial Shift involves higher sexual aggression rates reported by Millennial women compared to older generation women, in conjunction with lower rates reported by Millennial men compared to older generation men. We speculate that the Millennial Shift reflects changes in the traditional sexual script.