Penn State sophomore Ricky Morales and his roommates worked it out themselves: If the others are asleep, it's OK to have sex with a partner in the room.
"It's all about communication. That's what it comes down to," said Morales, a journalism major from Stroudsburg, Pa.
But at Tufts University near Boston, students apparently weren't able to negotiate such delicate matters so deftly.
After receiving about a dozen complaints in the last several years from a student body of 5,000, the upscale private university this fall took what is at the very least an unusual step in the world of college housing: It banned in writing sex with a roommate present.
Some students in Pennsylvania and New Jersey thought the policy sounded like a good idea.
"Sex should never have witnesses. Then it's just porn," said Fleurette Louis-Jacques, 20, an English and French linguistics double major at Rutgers University.
She and her roommate haven't discussed the topic, she said, but added that they don't have sex: "Seriously, not even being funny, we're like nuns."
Most students, however, thought that a written policy was unnecessary.
"Everyone here is smart enough to understand that it's a common courtesy" to leave the room while your roommate is having sex, said Doug Mocik, a freshman English major at La Salle University, ". . . unless your roommate is a freak."
Temple University senior Jordan Ramsey was incredulous that a policy would be needed. Told about the Tufts ban, he quipped: "Somebody wasn't getting any!"
Even some who have fallen victim weren't upset.
Ashley Clark, a senior business-law major at Temple, said she once had a roommate who would have sex while Clark was asleep. Clark sometimes woke up. She thought it was "weird, but it didn't bother me."
Kelly Powell, 21, a history and women's and gender studies double major at the College of New Jersey, had it happen to her, too.
"I didn't really care that much, as I was sleeping at the time," she said, "but I discussed it with her afterward and told her that it could not happen again."
Then there were those who thought sex with a roommate close by was something to be celebrated.
"You've got to get fist pounds," said Cory Winkoff, a junior communication major at the University of Pennsylvania.
He and a group of friends high-fived one another when the subject was introduced.
"We're happy when our friends are hooking up," agreed Terry Kennedy, a junior political-science major. "It's college; it kind of happens."
Most schools surveyed have no specific policy on sex in a room, but many ban behavior that offends a roommate.
"Our residence-life guest policy prohibits guests in a room over the objections of a roommate regardless of the activity," said Sandy Lanman, a spokeswoman for Rutgers.
Adrian Gage, an officer in the American College Personnel Association, said he wasn't aware of other schools with a ban like Tufts'.
The issue, said Gage, a student-affairs assistant dean at Worcester State College in Massachusetts, "may be part of a roommate contract or roommate agreement where it's one of the things listed that the two roommates can discuss."
Even religious institutions are not as specific as Tufts.
Neumann College and Villanova University, both Catholic, note in their handbooks that they adhere to church teachings, which condone sex only in marriage, and that those teachings govern residence-hall life.
La Salle, also Catholic, requires members of the opposite sex to leave a room by midnight Sundays through Thursdays and by 2 a.m. Fridays and Saturdays.
"Roommate approval is required for any residential student to bring a guest to their residence/room," spokesman Jon Caroulis said.
The College of New Jersey requires written permission from a roommate to have an overnight guest, but doesn't specifically address sex.
"We don't actually really get that many complaints" on the topic, spokesman Matthew Golden said.
Most schools report some complaints and said that the subject does cause some breakups, but that it was not one of the most prevalent concerns.
"General disrespect for each other comes up more often than anything else," Gage said.
At Temple, roommates have agreements and are asked at the outset about preferences regarding intimacy, said Michael D. Scales, associate vice president for university housing and residential life.
"We use that as a basis to establish what is acceptable," he said.
Scales said he and his staff had discussed Tufts' policy.
"Tufts is private. We have to be mindful of the freedoms and liberties that come along with being a public university," he said.
At Tufts, where about 2,200 students live with a roommate in university housing, no penalties are attached to the guideline, which appears as a new bullet in the campus-living handbook and was publicized last week.
It reads: "You may not engage in sexual activity while your roommate is present in the room. Any sexual activity within your assigned room should not ever deprive your roommate(s) of privacy, study, or sleep time."
Meanwhile, Morales and his roommates at Pennsylvania State University will continue to handle the matter on their own. They have a backup plan if a roommate is awake in the room.
"All you need to do," Morales explained, "is send a text message to that roommate to ask them for a half-hour alone."