He's considered one of the sexiest stars in the country music world and he also has one of the sexiest women in the entertainment industry that he calls his girlfriend, yet it looks like Blake Shelton is dealing with some major insecurities here. In fact, there's even a new report that says The Voice star is so insecure about his body and his weight that he refuses to be seen shirtless in public.

Sources close to Shelton say that even though he dropped over 30 pounds after announcing his divorce to ex-wife Miranda Lambert (which he even dubbed the "divorce diet), he still doesn't have the body confidence that other stars in the celebrity world have, especially when it comes to the paparazzi. Both Shelton and Stefani were spotted enjoying a little quality time at a pool, with the country singer wearing an oversized maroon shirt in the water.

"He is so sensitive about his weight," a source told Page Six on Wednesday about Shelton's pool look. "You will never see him shirtless."

The insider added that when it comes to being on the set of NBC's The Voice, "backstage . . . he always keeps his dressing room closed. At photo shoots, he will not change on set. He goes back to his dressing room whenever he needs to take his clothes off. But, he is not in bad shape. He's just so shy about showing off his body."

The tipster further explained, "Adam Levine will take off his shirt - and his pants - in the studio. Christina Aguilera also doesn't even care."

So far Shelton has not made any comments about the rumors -- nor has he showed us any shirtless photos of himself, either.

Tags: Gwen Stefani Blake Shelton