Her bra was unhooked. His pants were unzipped. Their intertwined bodies rocked to the rhythm of the Spotify sex playlist. “We have to stop,” Shri Amarnath said, interrupting the heat of the moment. “I don’t have a condom.”

It was a one-night stand and Amarnath wasn’t going to risk having to take plan-B a second time. “I didn’t want to take the chance,” the 21-year-old Indiana University student said. “I wasn’t trying to make babies with a stranger or get diseases from him.”

Refusing to have sex without a condom makes Amarnath somewhat of an anomaly. Only one in four vaginal sexual acts are protected by condoms, according to the National Survey of Sexual Health and Behavior Promotion, conducted by researchers at Indiana University. While unintended pregnancies are at an all time low, cases of chlamydia and gonorrhea are spiking. By age 25, one in two people would have acquired an STI.

“Historically, there is an image that condoms decrease satisfaction,” said Dr. William Yarber, an AIDS/STD prevention researcher at Indiana University. “But I think the idea that condoms interfere with sexual pleasure is being challenged.

To popularize condom use among young adults, the Indiana University Kinsey Institute Condom Use Research Team (KI-CURT) developed a series of interventions based on data from over 50 publications relating to errors, problems, and contextual factors that impact condom use. Currently, the team is working with heterosexual couples to “increase pleasure through latex” in the third intervention program, called The Home-Based Exercises for Increasing Responsible Sex (THEIRS).

“We’re working on interventions that really emphasize associating pleasure with condom use,” said Yarber, a member of the KI-CURT team.

Heterosexual IU couples between the ages of 18-24 were recruited to participate in the intervention over the university’s spring break. For a stipend of $60 worth of gift cards and condoms, 27 couples were selected to complete a titillating series of homework assignments. Over the course of four weeks, they will describe their experience using ten different lubricants and condoms.

Yarber was surprised he had to turn away disappointed couples interested in participating in the study. “It just shows that younger people want to protect themselves, but they don’t know much about the topic and the issue.”

A major factor deterring condom use is the idea that it’s linked with decreased pleasure. “I don’t feel the difference,” Amaranth said, but she understands why men feel uncomfortable.

Interestingly, research from KI-CURT found that nearly 35 percent of heterosexual couples actually used condoms to maximize pleasure. “It increases satisfaction because they don’t have to worry about risk as much,” Yarber explained. “They can feel more relaxed and expressive and not have to be concerned about pregnancies or STIs.”

Following the success of the first intervention for males, called Homework Intervention Strategy (HIS), KI-CURT carried out a second program for females, called HERS. Women were given a variety of condoms and lubricants to experiment with at home using their fingers or a dildo.

Both men and women were surprised by the plethora of condoms available and realized they liked some better than others. Yarber says that even when contraceptive use is taught in high schools, students don’t always pay attention.

“They’ll go to the drug store and buy whatever is available, or to the student health center and get whatever is free,” Yarber said. “They don’t understand that there are a lot of choices or how to use them.”

The intervention opened doors for women. One participant said she felt more appreciative of her sexuality, and no longer felt apologetic about desire or protecting herself. “That’s a blessing that a woman achieves that,” Yarber said. “I mean, it’s a gift she’ll use the rest of her life.”

Although rampant among young adults, many sexuality active individuals believe they’ll never get infected. “They think that STDs occur to other people, but not them,” Yarber said. They also might have a false perception about the STI status of their partner because they look healthy. But not all relationships are exclusive, Yarber warns. There may be an unknown partner.

Most people underreport their sexual histories and the number of partners they have, particularly in the heat of the moment. “You have to make the assumption that people aren’t going to be totally honest,” Yarber said.

Despite the increase of STIs, Yarber is optimistic that more women are becoming assertive about using condoms for their protection. “I mean, they may not let the guy in unless he has a condom,” the Kinsey Institute researcher said.

When Amaranth refused to “let the guy in,” he ran to the gas station without hesitation. Before restarting the music, she asked him if he was clean. “Even if we’re using a condom, I always ask,” she said. “It’s for my own peace of mind.”

Preliminary feedback from HIS, HERS and THEIRS indicated that the intervention programs spurred communication about sexuality. Once all the data is analyzed, KI-CURT hopes to apply for federal funding to conduct clinical trials.