Sometime between the founding of a student-run porn magazine and the day the campus health center advertised "Free Lube," Harvard University seniors Sarah Kinsella and Justin Murray decided to fight back against what they see as too much mindless sex at the Ivy League school.

They founded a student group called True Love Revolution to promote abstinence on campus. The group, created earlier this school year, has more than 90 members on its Facebook.com page and drew about half that many to an ice cream social.

Harvard treats sex — or "hooking up" — so casually that "sometimes I wonder if sex is even a remotely serious thing," said Kinsella, who is dating Murray.

Other schools around the country have small groups devoted to abstinence. On most campuses, they are religious organizations. Princeton and the Massachusetts Institute of Technology have Anscombe Societies, secular organizations named after an English philosopher and Roman Catholic. True Love Revolution is secular as well.

Some feminists, in particular, have criticized True Love Revolution's message.

Harvard student Rebecca Singh said she was offended by a valentine the group sent to the dormitory mailboxes of all freshmen. It read: "Why wait? Because you're worth it."

"I think they thought that we might not be 'ruined' yet," Singh said. "It's a symptom of that culture we have that values a woman on her purity. It's a relic."

Others on campus have mocked the group. Murray said his friends take pleasure in loudly, and graphically, discussing their sex lives just to taunt him.

"On campus there is such a strong attitude of pluralism and acceptance, but then it doesn't extend to this," Kinsella said.

In the student paper, The Harvard Crimson, columnist Jessica C. Coggins praised the group's low-key approach and scolded Harvard students for their "laughter at the virgin." She said students on the campus, which has 6,700 undergraduates, should "find a different confidence booster than making fun of celibate peers."

True Love Revolution members say the problem starts with the university. They say Harvard has implicitly led students to believe that having sex at college is a foregone conclusion by requiring incoming freshman to attend a seminar on date-rape that does not mention abstinence, by placing condoms in freshmen dorms, and by hosting racy lecturers. (Harvard students have also launched H-Bomb, a magazine featuring racy photos of undergraduates.)

"Sometimes that voice on campus is so overwhelming that students committed to abstinence almost feel compelled to abandon their convictions," Murray said. He acknowledged he "slipped up" and had sex earlier in college but said he has returned to abstinence with Kinsella.

Dr. David Rosenthal, director of Harvard health services, disputed the notion that the university promotes sex.

He said students mistakenly think everyone on campus is having sex. The National College Health Assessment Survey, which included Harvard and hundreds of other campuses, found that about 29 percent of students reported not having sex in the past school year. For the 71 percent who are having sex, it is crucial to promote safety, Rosenthal said.

"Some students may have a feeling that acknowledgment is condoning," he said, "and it's not."