TIGER WOODS’ ex is so furious about the golfer’s half-naked fishing outing with new girlfriend Lindsey Vonn that she’s threatening to take him back to court, say sources!

A shirt­less Tiger, 37, and his scantily clad skiing sweetheart, 28, were photographed letting it all hang out as they enjoyed the afternoon of May 14 aboard his 61-foot yacht, Solitude, off Jupiter Island, Fla. While ex-wife Elin Nordegren doesn’t care who Tiger dates, she’s livid because their kids – daughter Sam, 5, and son Charlie, 4 – were with him, a source says.

As part of their 2010 divorce, the couple agreed to keep the kiddies away from romantic partners AND publicity. Now, a source says Elin, 33, has ordered her attorneys to find out if Tiger’s boating antics are grounds for an injunction.

“Elin’s furious,” the source told The ENQUIRER.

 “She feels Tiger is using their kids to repair his damaged image by appearing with them and Lindsey in a place where he knows photographs will be taken. She wants to get an injunction to prohibit Tiger from exposing the kids to any publicity, especially when he’s with one of his girlfriends.”

According to the source, Elin said: “It’s bad enough that Tiger splashes his new relationship with Lindsey all over Facebook, but we had an agreement – no publicity with the kids and his girlfriends. Not only has he broken that agreement – they’ve hardly got any clothes on!”

FOR ALL the DETAILS and to see the pics that made ELIN flip – pick up the new ENQUIRER!