While military sexual assault and sexual harassment have been part of the media focus since 2013, it has been going on far beyond when women were allowed to serve in the military. Yes, men have been sexually assaulted and harassed in the military, and in some estimations and dependent on the years more so than women.
For more direct data, please look at www.sapr.mil/reports. Unfortunately that their reporting only goes back to 2004. At the end of this page, there will be more links to articles and testimony that can fill in the gaps on military sexual violence prior to 2004.
Tailhook scandal | United States history | Britannica
– TESTIMONY ON SEXUAL ASSAULTS IN THE MILITARY (govinfo.gov)