Whats the worst that could happen?

Did not get that impression at all. To me it seems like basically the same thing as the "What have you done, Billy?" and "dumbest man alive" memes. Something relatably annoying followed by a hyperbolic "haha if only" response.

Harassment is continuing once being told "no." There are a few frames missing from that comic for it to count as harassment.

It would seem the author is conflating sexual harassment with random flirting with women. It also sends the message that the author thinks it should be okay to flirt with random women as they go about their day/job, which is inappropriate, creepy, and annoying. He should probably try treating women like humans and develop a healthier sense of boundaries. He might have better luck.

The male character is a creep

Don't flirt with people when they're working. It's gross and predatory because they're basically a captive audience.