RYAN SEACREST has flipped for Justin’s Bieber’s ex-girlfriend, Selena Gomez!

The saucy “Spring Breakers” hottie apparently caught Ryan’s eye when she dropped by his L.A. radio show. But at 38, sources say the “American Idol” host is afraid he’s too old for the talented 20-year-old singer.

“SELENA SHOWED UP looking super-sexy in a low-cut top, and she totally flirted with Ryan,” said an insider.

“At one point he asked her if the lyrics to her new single, ‘Come & Get it,’ were about the Biebs, and Selena said, half-joking, that they were actually about him!”

After the interview, Ryan – who recently split from former “Dancing with the Stars” pro Julianne Hough – told pals that he’d love to ask Selena for a date, said the source.

“Ryan thinks they would have a great time together,” revealed the source. “The problem is he’s afraid that she’d laugh and tell him he’s old enough to be her dad – which, in fact, he is.”

Despite that, Ryan hinted to Selena’s people that he’s interested, hoping to sidestep the embarrassment of asking her directly and being shot down, said the source.

“Ryan is used to dating younger women,” the source continued. “After all, Julianne was just 24. So dating Selena wouldn’t be that much different.

“I’m sure that if Selena’s pals tell Ryan she’d go out with him, she’ll be getting a call. Selena’s expressed interest in seeing older, more mature men, but I’m not sure that means she’s looking for someone who’s pushing 40!”