Michelle Williams says she had better things to do than attend Kelly's birthday.

There have been rumours for a while now that Michelle Williams and Beyonce were not on the best of terms after Michelle slammed Beyonce's new album and Bey cropped Michelle out of a picture on Instagram. Then Michelle was mysteriously missing from the birthday party Beyonce threw for Kelly Rowland on February 11th.

After fans tried to clown Michelle for being left off the guest list, she fired back by saying she had better things to do. Her tweet below...

Later she explained she had to attend her niece's 1 year birthday party. See more tweets after the cut...