Katie Cassidy Twitter - "Arrow" star Katie Cassidy grabbed major social media attention on Sunday after she tweeted a comment about Erin Andrews. But what made it more interesting was Chrissy Teigen's reactions to Cassidy's posts. And after a few exchange of tweets, real life mean girls were unleashed.

Katie Cassidy got into a nasty Twitter beef with Chrissy Teigen after she criticized Erin Andrews' reporting skills during the football game between Seattle Seahawks and Green Bay Packers. According to The Daily Mail, Teigen defended her best friend Andrews, causing her to ignite a social media catfight.

The Katie Cassidy-Erin Andrews Twitter faceoff came when Cassidy criticized sportscaster Erin Andrews' post-game interview with Seahawk's star cornerback Richard Sherman, who stayed on the field in spite of an elbow injury. But Los Angeles Times revealed that Stephen Amell might be the one responsible for the altercation between the two beauties.

"@ErinAndrews should ask Richard Sherman why he stayed on the field while he's a physical liability," Amell tweeted, in which Cassidy responded, "Seriously, why isn't she doing her job?? @amellywood @BrandonStrabley @ErinAndrews."

After Cassidy's social media post, Chrissy Teigen reacted and defended her best friend.

"@MzKatieCassidy JOB [noun] : the work a person does regularly to make money. alt: what @ErinAndrews has. 2nd alt: What you don't have. Bye!" Teigen wrote.

After the exchange, Katie Cassidy and Chrissy Teigen's Twitter spat, did not end there. Us Weekly reported that the tweets continued to get nasty. And at some point, one of Cassidy's tweet made Teigen swung back on her making it another major ruckus.

"@chrissyteigen we always have been. Welcome to the party!" Cassidy posted, in which Chrissy responded, "@MzKatieCassidy own it. I'll take you seriously when you don't simultaneously talk shit and preach the gospel."

But two of Cassidy's tweets have eventually silenced Chrissy Teigen.

"Just to be clear, Your profile reads: "Gold digger and Stuff". You're asking me if I have a job? I'll send you a book. @chrissyteigen" Cassidy tweeted. Before adding, "For those of us who don't know Book(n) -a written/printed work consisting of pages glued or sewn together along one side and bound in covers."

Throughout the Katie Cassidy Twitter exchange with Chrissy Teigen, Erin Andrews, who is currently dating Cassidy's ex Jarret Stoll, has remained silent.