Adele reportedly met up with Celine Dion in London last night before the Canadian star went on stage.
According to The Sun, the My Heart Will Go On singer then teased the crowd at her gig by saying she had always wanted to sing with someone - before performing a verse of Adele's hit 'Hello'.
But the paper says their source claims Adele would be too scared to perform with Celine.
The insider said:
"Adele made the trip to meet her idol and the music legends both embraced in a private room backstage before the gig and told each other how much they loved each other.
Adele said she would love to sing with her on stage at some point but she would be too scared."
Celine recently revealed to showbiz journalist Dan Wooton that she would like to collaborate with the British star.
"Adele, hello, it's me. I was wondering if you can sing a song with me. Anywhere, any time."