Simon Cowell is reportedly worried Harry Styles will get "sucked into" the Kardashian clan.

The One Direction heartthrob is thought to be romancing Kendall Jenner, who is the half-sister of reality TV siblings Kim, Kourtney and Khloé Kardashian.

While Kendall's mom Kris is thought to be delighted by the pairing, Simon is said to have his worries about the 20-year-old's relationship.

"Simon knows Harry and Kendall's relationship is great for One Direction's profile, but he's wary of Harry being sucked into the Kardashian circus," a source told British magazine Star.

"He warned him that won't do him any favours long-term."

Harry is thought to have spent his 20th birthday, which he celebrated on February 1, with Kendall in Malibu, California.

They've been spotted together on several occasions and during a recent concert in Los Angeles they appeared to be cuddled up.

While Simon might not be sure about the singer appearing on Kendall's show, Keeping Up with the Kardashians, Kris is thought to be far more excited at the prospect.

"Kris has always seen her children's relationships as business opportunities, so she wants him on the show. She insisted Kendall talk to him about it and has also made inroads, explaining what a great opportunity it would be for him," a source revealed to Britain's Grazia magazine recently.

Kim's former relationship with ex-husband Kris Humphries attracted a lot of viewers to the show, while her current partner Kanye West is more reluctant to be featured.