At this point, you've no doubt heard some 'interesting' thoughts on men pursuing women sexually versus sexually harassing them. The discourse around the subject is sometimes maddening, with people conflating the two or discussing them like there's a spectrum ranging from making eye contact to rape. Um, there is not. The intention to gauge someone's sexual/romantic interest is different from the intention to harass or assault them, no matter what your 'Fox News'-addled uncle says.
Comedian Kate Willett clearly articulated the difference between flirting and harassment in a Facebook post that went viral, and which she later posted to Twitter.