Adele forgot her own song lyrics during a concert in Lisbon, Portugal.

The London-born singer said: "S***, wrong words. S***, s***, s***. I started singing the verse instead of the chorus! Sorry!"

Despite being one of the world's biggest pop stars, Adele has a history of forgetting the lyrics to her own chart-topping tunes.

In 2011, for instance, she stopped during a performance of 'Chasing Pavements' and acknowledged to her fans in Boston that she couldn't remember the next line of the song.

She said: "I forgot the words! Oh my god, I've never forgotten the words to that song!"

Meanwhile, it was recently reported that the 'Hello' hitmaker is set to sign a £90 million record deal.

Adele is believed to have been offered the jaw-dropping sum of money by Sony, who will release her music worldwide.

Assuming the figures are accurate and Adele accepts the offer, she will overtake the previous record held by fellow Brit Robbie Williams, who was reportedly given as much as £80 million by EMI Records in 2002.

An insider at Sony recently revealed: "We have secured the biggest music star in a generation. This is massive.

"Adele's deal with her original label XL expired and we'd an existing relationship with her in America.

"The deal is being worked on by our Columbia label in the US, but is worth £90 million and gives Sony the rights to release her future music exclusively around the world."