TAKING IT LIGHTLY. In her last Instagram post on the issue, Anne Curtis asked everyone to 'relax.' Instagram photo posted on the Anne Curtis Facebook page

MANILA, Philippines - On Sunday February 24, "national sweetheart" Anne Curtis celebrated her 28th birthday in the ABS-CBN musical variety show "ASAP 18."

Anne, known for her brand of sexy cuteness coupled with attempts at being a songstress (she has an album and a sold-out concert to her name called "Annebisyosa"), did a song number, of course.

She did a rendition of Rihanna's "Diamonds" clad in a sexy outfit that left little (or a lot?) to the imagination, true to Rihanna's style. Anne even donned Rihanna's current hairdo, too, without having an actual undercut.

But it seemed that people hardly noticed her singing or the water that rained over her as she sang. They noticed her outfit and, by Sunday evening, social media was abuzz with the question: Was Anne wearing underwear or not?

Watch the video of Anne's number here:

On February 26, the Movie and Television Review and Classification Board (MTRCB) posted these tweets:

MTRCB summons ASAP to gender-sensitivity investigation over alleged provocative outfit of one of its stars last Sunday.

— MTRCB (@MTRCBgov) February 26, 2013

MTRCB to investigate ASAP over provocative number and outfit of one of the show's performers last Sunday.

— MTRCB (@MTRCBgov) February 26, 2013

Citing its Memo of Understanding w/ABS-CBN, et al to ensure gender-sensitivity, MTRCB calls ASAP over provocative number.

— MTRCB (@MTRCBgov) February 26, 2013

On the ASAP issue, MTRCB shall always endeavor to give all concerned the chance to be heard.

— MTRCB (@MTRCBgov) February 26, 2013

On the same day, Anne posted a collage of her outfit on Instagram, shared on her Twitter account:

TAAAADAAA! I present to you the controversial @boomita outfit I wore for my birthday number on ASAP. As… instagr.am/p/WMINPkiopi/

— Anne Curtis-Smith (@annecurtissmith) February 26, 2013

Here's a screen shot of what Anne posted on Instagram:

OUTFIT COMPONENTS. The top is actually a bustier bodysuit that's high cut. The slit of the skirt, meanwhile, was high enough to reveal Anne's leg almost up to her waist, but not the lower part of the bodysuit.

Anne's description of the collage goes:

"TAAAADAAA! I present to you the controversial @boomita outfit I wore for my birthday number on ASAP. As you can see we have a bodysuit with a hidden tangga to make way for the sky high slit skirt. It is made out of 2 pieces. In fact the 'tangga' is made out of swimsuit material which Boom Sason is also known for making. I was completely protected.

"It may have seemed like a wardrobe malfunction to many but I can assure you, after making the mistake of not securing myself once I wouldn't let that happen to me again. :) So to settle all your minds I just had to post this.

"Thank you to everyone that was concerned! To everyone that's trying to make an issue out of it! Thank you! ABSCBN news just told me its their most clicked on video on their site ever!

"Just relax everyone! Wearing a tangga is no newbie in the industry! It's been around since the 80's :)"

Inquier.net reports that ABS-CBN's head of Corporate Communications Bong Osorio told them that they have received the MTRCB summons.

"ASAP representative will be attending a meeting set by the board on Thursday," Osorio told Inquirer.net. - Rappler.com