Washington: A controversial new sex app called "Bang With Friends" claims to facilitate sexual encounters with users and their Facebook friends without the embarrassment of rejection.

"Anonymously find friends who are down for the night," the company website said.

"Your friends will never know you're interested unless they are too!"

The Bang With Friends app, aimed at 20-somethings, was created by three "college-aged" men from California, who are withholding their identities, according to US media reports.

The app only alerts users of a potential hookup if both parties express interest by selecting what is called the "Down to Bang" button.

The creators of the app said it has already gained more than 30,000 users, registering five new users every minute according to a report on the online tech site Mashable.

Critics of "Bang With Friends" told RIA Novosti, putting the physical first is the reason for the demise of the majority of marriages and relationships in the US.

"Back in the days people would court, they would go out with different people without exploring the sexual relationship because it allowed you to get to know what you may or may not have in common," said Kristen Crockett, a Washington-based relationship coach.

And while some who use the app may be more interested in sex than building a relationship, Crockett cautions users with the potential drawbacks of getting physical with a Facebook friend.

"Once you start sleeping with someone, your red flags, your fears, all of those things get pushed into the back of your mind," she said.

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