KATE GOSSELIN is caught in a twisted “love triangle”!

She’s named her former bodyguard Steve Neild as her new busi­ness manager – and sources wonder if the increasingly cozy relationship between the two is troubling Steve’s wife, Gina.

“Gina recently posted a happy Facebook photo show­ing her and Steve and their children,” said an insider. “But Kate seems to be one-upping her, and she’s thrown caution to the wind. She and Steve have been spotted holding hands in public, and he’s even staying at her hotel.”

According to the insider, Steve, 52, is registered at the Trump International Hotel in Man­hattan, where Kate, 39, is filming “Celebrity Apprentice.” In fact, another source claims that when Steve’s room was called on March 30, Kate answered the phone. “They are most definitely a couple and NOT trying to hide it,” said an eyewit­ness who saw them with two of her kids at a March 2 Demi Lovato concert in Virginia. The insider added: “Gina has got to be wondering just what’s going on. She was hoping that after ‘Kate Plus 8’ ended, Steve would finally be done with Kate, but she kept him on. It must be a never-ending nightmare.”

Gosselin’s reps deny there’s any romance. But The ENQUIRER has previously reported that Steve became a fixture at mom-of-eight Kate’s Wernersville, Pa., home after her 2009 divorce from ex-hubby Jon.

“He’s been functioning as her de facto ‘husband,’ and he’s like a second father to the kids,” said a source. In fact, the New Zealand native was so busy with Kate, he rarely even saw Gina, who lives three hours away in Maryland.

The following summer, Kate and Steve took at least seven trips together, including one to Bald Head Island, N.C., where they took sunset strolls on the beach. They also spent time in Mexico – without Kate’s kids.

“Gina certainly has to be re-evaluating just how strong their marriage is,” the insider noted. “It’s as if she’s found herself in a ‘love triangle’ that she wants no part of.”