Madonna say she wears a grill on her teeth to “p*ss people off”.

The singer took son David Banda to the Grammy Awards on Sunday night, and both mother and son wore matching outfits, with Madonna also wearing a grill.

According to the star, she often wears a grill because she knows people criticize her for it.

"Yeah, I'm grillin'. It p*sses everybody off when I wear my grill, so that's why I wear it," she told E! News on the red carpet, adding that she dons the mouth gear "when it matches my outfit. When I don't have to eat. Actually, I've learned to eat with my grill in.”

Although David says he asked his mother to buy him a grill for his birthday, time constraints have got in the way. While Madonna isn’t against the idea, she claims it’s simply a matter of scheduling.

"I know, but we haven't had time. We have to go to the dentist to get a mold!" she explained.

The pop legend took the stage on Sunday night with Macklemore for a performance of his hit single Same Love. 34 couples got married live on TV during the song.

"I wouldn't do any old song with any old artist, but I feel like history is going to be made tonight," Madonna said. "So I want to be part of that.”

The 55-year-old went on to explain it was David’s idea for them to wear matching outfits for the ceremony. The pair both wore black trouser suits and hats, while Madonna accessorized with a cane.

“We're both working the Ralph Lauren angle," she revealed. "For this look, I followed his lead. He dressed me tonight. He wanted me to dress like him, so I obeyed him."