Britney is rumoured to be getting back at her ex by writing a revenge song.
This comes after Justin had a barely-disguised dig at her in his hit, Cry Me A River.
Getting her own back
But now Britney's getting her own back.
It's said that the pop princess has written a track called ClubSong, and it's all about her first love. Rumours say it could appear on her next album.
'Twisting the story'
The lyrics say:
"Playing me publicly, twisting the story, see, made it the talk of the town.
Then she sings: "Cry me..Cry me...done. Here's a bridge to walk over it too."