I use to think it was Taeyeon who had beef with Jessica and she was the one who got Jessica kicked out of the group.
And while there definitely was something going in between those two I think the real villain of the peice might have been Tiffany.
Tiffany was the one who seemed to instigate a lot of the drama between the two. It almost felt like Tiffany thought for whatever reason there was only room for one American on the roster. Its possible Tiffany was pitting those two against each other for her own benefit. She was jealous of Jessica and her star power and wanted herself to be Taeyeons bff.
I saw a video on YouTube of all Tiffany shady moments against Jessica and it was NOT COOL.
Where do you stand on this issue?