Watching porn also heightened Q.’s performance anxiety. “You are looking at an adult,” he told me. “The guys are built and dominant and have a big penis, and they last a long time.” And if you don’t do it like the guys in porn, Drew added, “you fear she’s not going to like you.”

Leaning back in his chair, Drew said some girls acted as if they wanted some thug rather than a smart, sensitive guy. But was it true desire? Was it posturing? Was it what girls thought they were supposed to want? Neither Q. nor Drew knew. A couple of seats away, a sophomore who had been quiet until then added that maybe the girls didn’t know either. “I think social media makes girls think they want something,” he said, noting he hadn’t seen porn more than a handful of times and disliked it. “But I think some of the girls are afraid.”

“It gets in your head,” Q. said. “If this girl wants it, then maybe the majority of girls want it.” He’d heard about the importance of consent in sex, but it felt pretty abstract, and it didn’t seem as if it would always be realistic in the heat of the moment. Out of nowhere was he supposed to say: Can I pull your hair? Or could he try something and see how a girl responded? He knew that there were certain things — “big things, like sex toys or anal” — that he would not try without asking.