Rihanna appears to be pregnant with her first child, and all of social media is talking about it. And while Rihanna is not openly talking about her alleged new pregnancy - she's not hiding it either.

Last night Rihanna performed at her annual Angel's Ball charity dinner and wore a form fitting dress that clearly showed her belly bulge.

The rest of Rihanna's body was skinny - and it was just her belly that was protruding.

Here's the video that's making the rounds online:

MTO News spoke with multiple people at the event, and they all confirmed that Rihanna - who is known for heavy drinking - was not drinking that night.

Here's Rihanna pretending to drink some wine - but not sipping any of it:

So how can we be so sure that Rihanna is pregnant? We asked one of Rihanna's reps about her bump, and instead of getting a "no" . . . we got a "no comment."

Rihanna has been dating her longtime boyfriend Hassam Jameel - a Saudi billionaire - for more than three years and they share a home together in London.

Below are some pics of Riri at the event.