If ever there is any word that should be used to describe singing sensation Rihanna, it would be "cool." She is, after all, the embodiment of the word. And now, it's not only her fans who know it but also her co-stars in the movie "Ocean's 8."

Refinery 29 reports that it seems that some of the actresses acting with her have become starstruck with the pop singer. Sarah Paulson, who is an Emmy-nominated actress and regular mainstay of the cult TV anthology series "American Horror Story" has admitted that there is one thing that she keeps worrying about when shooting a scene with the singer.

It seems that the hardest thing to do when with Rihanna is to not sing or hum her songs! Which is of course hard as Rihanna has too many songs that have become popular internationally. And Paulson is not the only one who seems to have this problem. She admits that most of the people on set have conversations in how they are making sure they are not singing Rihanna songs.

It seems that this is one thing that the co-stars have bonded on. Which is a good thing, as it seems that the producers of the star-studded movie are afraid that with an all-female lead, there might be some catfights that are bound to happen.

Mstars News reports that in order to avoid this, they hired a therapist to monitor the women on set. The site claims that some of the people involved in the project are not getting along. Could this be the rumored rift between Oscar winners Cate Blanchett and Anne Hathaway?

The rumors of the feud between the two on the set of "Ocean's 8" have already been denied. But the presence of the therapist might say otherwise. Do you think there is truth to the rumors of a catfight between the stars? Share your thoughts and comments below.