New Delhi, Feb 6 : Pop star Rihanna is utterly bowled over by beau Chris Brown, and just cannot let him out of her sight for even a tiny moment.

The `Umbrella' hitmaker, who began dating Brown in a year back, likes her beau to be around her round the clock, reports the China Daily.

"She has to have Chris around her 24/7. If Chris is with her on a photo shoot and steps away for a second, she starts saying, ''Where did he go?" a source told OK! Magazine.

"If Chris isn''t with her, she wants to call and check in every second. She''s crazy about him. Rihanna constantly talks about Chris," the source added.

Rihanna has herself confessed that it is very difficult for her to stay away from her family and loved ones, and be by herself.

"My biggest challenge is being away from my family and friends, and all the people I love and I''m used to being around. It''s hard for me to just throw that all away and be by myself," Rihanna said.

Meanwhile, during Brown's recent London concert, Rihanna reportedly banned a host of beautiful female stars from meeting him backstage. (ANI)