It seems the rift between Katy Perry and her bestie Rihanna is deeper than we thought. We recently reported that Perry heartily disapproves of RiRi's reunion with Chris Brown. But as RiRi said, it's her mistake to make. However, the gap between the once-close ladies has widened to the point that Perry refused to sit next to Ri at the 2013 Grammys on Sunday, Feb. 10.

The staffers that were in charge of the seating at Music's Biggest Night had to deal with a "headache" and shuffle the former BFFs so they didn't end up seated next to one another.

“They aren’t tight anymore because Katy doesn’t approve of Rihanna dating Chris Brown," a source close to the sitch told Us Weekly (quote via Hollywood Life.)

The pop divas, who spoke about eventually doing a song together, haven't been seen hanging out in public since the VMAs and that was all the way back in September.

So something is clearly afoot in their friendship.

But our gut tells us that RiRi won't be altering her behavior to placate Perry when it comes to Breezy. Rihanna is doing exactly what she wants when it comes to her man and she doesn't care who disapproves. As long as she was seated next to Breezy, she was probably happy.

Watch the Rihanna 'Stay' Video