15 million hits -- that's how many people have watched YouTube sensation Keenan Cahill rock out to Katy Perry. "You think I'm pretty without any makeup on... you think I'm funny when I tell the punch line wrong..." Move over Justin Bieber - there's a new sensation in town. Although he's not producing any original material, he's quite the hit-maker. Lip-synching songs from Lady Gaga to Usher. His latest venture -- cable. After seeing his videos, E!'s Chelsea Handler says she just had to have him on her show. He's a quick clip -- and he's quite the flirt. HANDLER - "Is this helping you out with a lot of attention like at school and stuff. I mean with girls?" CAHILL -- "Essentially one girl who's blonde, funny, comedic, who's one E!, who's a cougar. Here's my number." HANDLER -- "You're the only person allowed to call me a cougar." Not only was he on the show, he recorded a song with a famous fan backstage at the Chelsea Lately studio - cleverly designed to look like his bedroom, fooling a lot of people. HLN has the scoop. "That's where they premiered Keenan's latest lip-synch doing a 50 cent rap when who should appear in his bedroom -- 50 Cent himself. The rapper even gave Keenan his cross. A new sidekick for 50 Cent." Speaking of 50 Cent, his stint on Handler's show has fueled the flames of those dating rumors. The Daily Mail point out the duo have been dodging questions for weeks -- and this latest appearance isn't helping. "He is not doing much to quash the Chelsea ...