I need some advice about a co-worker

I have a serious problem w/ one of my managers. He is only one notch above me, so im not scared of his position. Here's the problem. He stares at young girls asses all the time, then he'll look at me and grin. Hes an asshole. He does it all the time. He told one of my co-workers that she is so sexy with her hair down. In one sentence, he sexually harasses way too much. Nobody is doing anything about it either. Im wondering if I should be the one to report him, even though he never sexually harassed me, luckily hes not gay i think. I am thinking of reporting him today, what do yall think?