The subject was pickup lines, and Germany's "Mr. Flirt" offered a few examples to his class of Syrian and Iraqi refugees. "I really love the scent of your perfume," he suggested. "You have a beautiful voice." He invited his students to take a stab.
Essam Kadib al Ban, 20, raised his hand. "God created you only for me," he said, then tried another: "I love you. Can I sleep over at your place?"
Horst Wenzel winced, but caught himself quickly.
"Don't tell them you love them at least for the first three months of your relationship, or they'll run away," he explained patiently. "German women don't like clinginess."
Wenzel, 27, makes his living teaching wealthy but uptight German men how to approach women. But this year, he decided to also volunteer his skills to help Germany as it struggles to integrate more than 1 million refugees who have arrived over the past two years, most of them from war-torn Muslim countries with vastly different relations between the sexes.
"Finding a relationship is the best way to integrate, and that's why I'm giving these classes," Wenzel said.
Last week, in downtown Dortmund, he offered his third installment of "How to fall in love in Germany," taking 11 young men through the paces. The students conceded they had a lot to learn.
Omar Mohammed, a shy, 24-year-old goldsmith from Syria with spiky black hair and almond-shaped eyes, said he's attracted to German women, with their Nordic looks and punctuated accents. But they remain a mystery to him, and he has no idea how to approach them.
"It's hard to meet a girl when you don't speak the language well and can't really talk to them," he said. "There are a lot of differences, not only the culture and religion — we just don't have this total freedom at home."
Still, he said, "I'd love to marry a German woman and live with her. She could help me with the language, and she knows the place and the laws much better than I do."
Some German women were receptive to the idea. Jasmin Olbrich, having a quick lunch of French fries at a food truck outside the educational center, said she liked the Middle Eastern looks and complained that German men "drink too much beer, watch way too much soccer and are just so white!"
But across Germany, hostility to asylum seekers has been on the rise since groups of foreigners — mostly young men from northern Africa — robbed and groped dozens of women on New Year's Eve in Cologne. Most of the hostility targets young male asylum-seekers from Syria, Iraq and Afghanistan, who make up the majority of the migrants reshaping Germany. Last year alone, 890,000 people applied for asylum, with hundreds of thousands more applying this year.
Violent crimes against migrants and arson attacks on asylum shelters and mosques have increased in frequency, and refugees say they have experienced discrimination and abuse since the Cologne attacks. The anti-foreigner sentiment is reshaping German politics as well, with the populist Alternative for Germany party surging as it campaigns against Chancellor Angela Merkel's decision to welcome the migrants.
The flirting class, participants said, offered a way to get beyond the adversity.
"We are really benefiting from the class," Kadib al Ban said. "The teacher is telling us how German women think, how to talk to them ... and understand their traditions."
Wenzel usually charges 1,400 euros ($1,500) for a private one-day class, or 4,000 euros for a group. The tall blond is an authority in Germany when it comes to the art of seduction, giving flirting advice on TV and radio. He says a half-million Germans follow his "flirt university" blog on how to find Mr. or Mrs. Right. For the migrants, Wenzel is volunteering his time in occasional classes across the country.
"A lot of the guys are absolute beginners when it comes to flirting, dating and sex," he said.
The class got off to a rocky start. The migrants, unsure what to expect, sat with their coats on and their arms crossed, eyeing their cheerful coach suspiciously.
Wenzel chatted about pick-up lines, paying compliments and original ideas for first dates. Impress and entertain the girls, Wenzel advised. Invite them to the theater, rock climbing, a concert, or take them on a trip to London or Amsterdam. That last piece of advice would probably work better for Wenzel's regular clientele of rich Germans; asylum seekers aren't allowed to leave the city they're registered in, and don't have the money to travel in any case.
Then he moved on to sex.
"Men and women have sex all the time — on the first, second or third date, that's normal." Wenzel said. "It's not a big deal in Germany."
The men in the room giggled, but snapped to attention.
When Wenzel moved onto the differences between male and female orgasms and how to arouse a woman, they fell silent again. Several men blushed and others looked down at the floor in embarrassment.
One of the students became indignant, whispering in Arabic to his neighbor: "But having sex before marriage is a sin; it's haram!"
But there were moments of realization as well.
Asked how to impress a German woman, one student suggested getting ripped at the gym. Wenzel countered that most women don't go for the body-builder type. Another suggested picking up a date in a Ferrari. Wenzel said that would attract women interested only in money. The students readily agreed, perhaps because most were thin and quite aways from being able to afford a sports car.
When class let out, most of the men said they'd learned a lot and were eager to put their new skills to use.
But Kadib al Ban, the perky Syrian with the flowery pick-up lines, remained somewhat unconvinced.
"I'd happily have a German girlfriend," he said. "But when I get married, I want to have a girl from my country who shares my culture and my traditions."