No, hitting on people is not always harassment, even if the person being hit on finds it annoying. People get honestly confused about this stuff and if you’re one of them I quite understand. But claiming that all expressions of sexual/romantic interest are harassment only clouds the issues for those who are unclear.

Hitting on age-20 interns as someone who is effectively a supervisor is pretty cut and dried however. Creepily stalking them into their bedroom is less slam-dunk lawsuit worthy, but completely awful by any measure, and should guide a risk-averse company to put very strongly requirements on the transgressor even if they don’t care about doing the right thing.

And yeah, tacit acceptance through silence of borderline behavior is a big problem. Don’t let it be construed I’m trying to minimize here.