During Kanye's gigs in London with Jay-Z last week, Rihanna appeared on stage at the O2 Arena, but Kim wouldn't have a bar of her backstage.
"Rihanna wasn't even allowed to go into his dressing room without Kim being there," a source told The Sun.
"The fact she was linked to Kim's brother probably didn't help."
Rihanna was rumoured to have hooked up with the reality star’s brother Rob Kardashian in February this year and it seems Kim wants nothing to do with the 'Only Girl In The World' singer after this experience.
Rihanna isn’t the only one who's banned from hanging out with the rapper alone.
"Kim is incredibly protective of Kanye and doesn't want any women near him unless she is there even his friends," said the source.
"It's crazy but Kim knows the attention Kanye gets when he's on tour, and she doesn't want any competition."