But the behaviour continued, BuzzFeed News reported. The following day, Ms Nonnemacher was preparing to check out when the same male staff member blocked her on a staircase and gestured to her chest, chastising her for showing too much cleavage.
"He said, 'You're showing too much cleavage, it's not appropriate'," she told BuzzFeed News.
"There were people in the landing and the lobby around to hear. It's embarrassing, for one, and not that I should have to explain it, but I wasn't wearing anything provocative."
She said she was wearing a V-neck top, a shirt over the top of it, jeans and boots. And although she didn't think she outfit was provocative, she added: "Even if it was, it was very much victim-blaming — a ridiculous, misogynistic view."
Ms Nonnemacher said she checked out of the hostel, and then emailed the hotel's manager to report the incident.
The hostel's manager replied, saying he would investigate. But a second email from him left her furious.
"After investigation, I am really sorry to tell you that ... it turns out that you were dressed provocatively with a plunging neckline," the manager said in his email, which was shared on Twitter.
"This is a mistake, because when travelling and frequenting a hotel where there are many men, it is more prudent, to avoid any harassment to dress as well."
Ms Nonnemacher replied to the manager, saying his response was not appropriate.
The next email from the manager read: "What kind of girl are you? You don't recognise all what I said?! I am sorry, I can do nothing for you.
"You do what you want at your home, but not in a public area! My hostel is not a club to date and/or to have an affair!"
The tourist told BuzzFeed News that response left her with a "burning rage".
"It's a combination of being embarrassed and powerless and angry about it. You just feel like there's nothing you can do about it," she said.
Ms Nonnemacher said she shared her experience and the correspondence between her and the hostel on Twitter and Facebook saying she wanted to warn other female travellers considering staying there.
"I just wanted to warn other girls who may want to stay there", she told BuzzFeed News. "If anything were to happen with one of their staff members, they don't respect personal boundaries — if you were dressed 'risqué' it's your fault.
"Stay away from this place — it's bad."
In a response to BuzzFeed News, Enjoy Hostel's manager Paul Benichou said the hostel was "trying to protect" Ms Nonnemacher.
"A young lady coming to the breakfast room and dressed very provocatively. We said, 'Miss beware cause it is a public area here, with many men and we want to protect you'," he said.
"We have made an action of prevention. That's all. And I was shocked that this client consider we process harassment. It was not that at all. Exactly the contrary!
"I consider men and women are equal, strictly. But women are prey in our nice city. And need to be informed and protected. I do my job by protecting my guests.
"I was totally surprised she feels attacked, so I said to her it was a misunderstanding, that we are well educated and fair. I [apologised.] Now this lady has decided to make the buzz on internet to destroy our reputation?! It is a nasty attitude! Not fair at all. I am disgusted."
