AUSTIN — When the doors open at some University of Texas fraternity parties, young men and women need to hand over two items: a state-issued ID and their phone, with their Tinder University profile pulled up. If the students do not have a Tinder U profile, they are asked to create one, even if it means downloading the app for the first time — and even if they are in a steady relationship. No app, no entry.

“Simply scan to enroll!,” read a poster outside one party this spring, referring to a scannable QR code printed below a burnt-orange Longhorn. “Must: be within five miles of campus, be ages 18-22, have an existing Tinder profile, have UT Austin in your profile.”

As they race to sign up young adults who present their biggest growth opportunity, Tinder and Austin-based Bumble have stepped up their game on college campuses across the nation. Fraternities are deciding whether they’re a Bumble house or a Tinder house, and signing exclusive contracts. The dating apps provide money to cover production costs for parties, branded signage and swag. The frats provide access to thousands of potential new users — a trend that has gone unnoticed by parents.

“I think parents would want to know this,” said Joell McNew, president of Safehorns, a safety advocacy nonprofit comprised of UT parents, students and community members. “It’s an awareness issue. We’re still parents, regardless of how old you are.”

McNew said she has concerns about the safety of online dating, which encourages meet ups with strangers. On both Bumble and Tinder, millions of users swipe left or right to indicate interest in the profiles of nearby people. If two users swipe right on each other, they “match” and can start a conversation.

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It’s unclear how prevalent the dating-app fraternity sponsorships are, even in Texas. Tinder and Bumble declined to specify the scope of their campus involvement, though both said their apps have college marketing events across the country. Students who have been to parties at Oklahoma University, Tulane University and Northwestern University confirmed the events were sponsored by the apps.

Still, a UT associate professor who wrote her doctoral thesis on the e-dating market had never heard of the sponsored parties until a reporter told her about them.

While the sponsorships appear to be on the “down low,” they are a brilliant marketing strategy for dating apps, said Angeline Close Scheinbaum, an associate professor of advertising and public relations at UT. In addition to recruiting new users, the parties generate company buzz when attendees don brightly colored merch and share snaps from the event, where the apps’ logos are plastered on signs and flags in the background.

But there’s a difference between promoting your app and forcing someone to become a user, said Millie Lopez Stuessy, whose daughter attends UT.

“It’s one thing if the party is sponsored by these companies, but once they start forcing somebody to participate in their company in some way, I have a problem with that, because I don’t think that should be necessary to enjoy the event,” Lopez Stuessy said.

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A fraternity member with knowledge of the sponsored parties, who spoke on the condition of anonymity because he did not want to jeopardize his fraternity’s relationship with the company, called the partnerships “mutually beneficial.” He said the terms of the contract guarantee the frat a certain amount of money, with the opportunity to earn additional money based on the number of students who download the app at ticket pickup. He declined to specify the amount of money awarded in the contract.

“It’s pretty helpful,” the member said. “It allows us to do better things, it allows us to attract more people because of the cooler things we’re able to do.”

18- to 24-year-olds most likely to use dating apps

The sponsored parties are just one example of the growing presence dating apps have on college campuses. Bumble and Tinder recruit campus ambassadors — college students who promote the app on social media and in real life — including by helping to organize a sponsored fraternity party.

“More than half of our users are between the ages of 18-25, so college students are one of our core demographics,” a Tinder spokesman said in an email. “In addition to our Tinder U product experience, which connects users with other students first, we operate a student marketing internship program that focuses on on-campus partnerships, creative marketing activations and social media management. Through the program, we sometimes sponsor events with different social organizations on campus, which helps introduce — or reintroduce — our brand to new groups of people.”

At UT, both apps had a large presence at this year’s Roundup, a highly anticipated weekend filled with parties and popular performers. The annual event, which has come under fire for its long history of racism, is no longer sanctioned by the university.

“At UT RoundUp specifically, our brand ambassadors work hard to elevate students' experiences — whether it's offering safe rides for students to get around campus, passing out merchandise, such as ChapStick, sun visors, or fans, as well as supporting the fraternities in their endeavors,” said Samantha Fulgham, Bumble’s Chief Creative Marketing Officer, in an email.

“We encourage students to download Bumble in order to attend Bumble-sponsored events during RoundUp,” she added. “Not only does this give them an opportunity to connect with other students who may be attending the same event as them, but it also gives them an opportunity to connect outside of RoundUp.”

While the sponsorships go mostly unnoticed by those outside the college crowd, researchers say college-aged people are now more likely than any other age group to use dating apps.

Between 2013 and 2015, the share of 18- to 24-year olds who reported using online dating nearly tripled, increasing from just 10 percent to 27 percent, according to a 2015 survey conducted by the Pew Research Center.

Beyond appealing to their target audience, the sponsorships are successful because they are not school-sanctioned and do not occur on campus, Close Scheinbaum said. UT-Austin officials declined to comment on the partnerships between dating apps and member chapters of its Interfraternity Council, and the Council did not respond to requests for comment.

“If it was sanctioned by the university, I’d like to know, but there’s a lot of sponsorship going on of events that as a parent, I’ll never know about,” Lopez Stuessy said. “My child is over 18, and my child has to learn some responsibility in making choices of which events to attend, and it’s not my place at this point, anymore, to know who is sponsoring events.”

sami.sparber@chron.com