Does Harrasment happen for female emps to get better posting?

There has been scenarios in which a hard working smart employee doesn't get promotion or hike. Whereas few who are ready to share beds, go to pubs and do quid quo pro are getting every benefit out of it.

This highly demotivates the hard working female emps. So have u faced any such? Or do you know the full story of someone doing it ?

Bcoz at startups there is no time restrictions. Sometimes late night work happens and so many things are linked with it. I hope I don't need to elaborate.