This was a real hackathon presentation at TechCrunch Disrupt 2013 TechCrunch Disrupt TechCrunch co-editors Alexia Tsotsis and Eric Eldon just wrote an apology to all of their readers and TechCrunch Disrupt 2013 attendees for allowing two inappropriate presentations on stage earlier today.

TechCrunch Disrupt is a notable technology conference that draws speakers like Mark Zuckerberg and startup judges like Marissa Mayer.

Today, two presentations took the audience by surprise. One was called Titstare, an app two hackers called "titillating" and the "breast app ever." The founders, who are Australian, presented Titstare as a "joke." Their app shows pictures of people looking at cleavage.

Here are some of the reactions from the largely unimpressed crowd.

I can't image why some people think sexism is still an issue in the Tech Community #titstare — Jeffrey Davis (@penland365) September 8, 2013

Titstare guys got a very loud applause from audience. Thank god sexism isn't alive and well in the tech sector. SO PROUD TO HAVE MY KID HERE — Kim (@kkjordan) September 8, 2013

A guy pretended to orgasm on stage at TechCrunch Disrupt 2013 TechCrunch Later, another hacker got on stage and showed off something called "Circle Shake." It is a game to see how many times you can shake your phone up and down in ten seconds. But when the hacker demonstrated the app on stage, he started groaning and pretended to masturbate. It was disturbing for viewers, especially for those who brought children to watch the event.

Here is the Titstare presentation, below. Valleywag has the fake masturbation clip.

TechCrunch says it will do a much better job screening from now on. Here's TechCrunch's apology.

Normally our hackathons are a showcase for developers of all stripes to create and share something cool. But earlier today, the spirit of our event was marred by two misogynistic presentations.

Sexism is a major problem in the tech industry, and we’ve worked hard to counteract it in our coverage and in our own hiring.

Today’s issues resulted from a failure to properly screen our hackathons for inappropriate content ahead of time and establish clear guidelines for these submissions.

Trust us, that changed as soon as we saw what happened at our show. Every presentation is getting a thorough screening from this hackathon onward. Any type of sexism or other discriminatory and/or derogatory speech will not be allowed.

You expect more from us, and we expect more from ourselves. We are sorry.