Tiger Woods and Lindsey Vonn may be on the rocks already, after claims that she believes Woods is cheating on her, with his ex-wife, Elin Nordegren.

“Tiger says that Lindsey is convinced he’s cheating on her with Elin,” a source close to Woods told The Enquirer. “She feels betrayed and believes he is still in love with Elin. Lindsey’s not happy at all. She’s well aware that Tiger and Elin were having sex while they were discussing the possibility of getting remarried, and in her heart she’s convinced that they’re still at it.”

In March, the pro golfer announced his relationship with Vonn, alpine skier, via Facebook.

“This season has been great so far and I'm happy with my wins at Torrey and Doral," Woods said. "Something nice that's happened off the course was meeting Lindsey Vonn.”

The golfer added, “Lindsey and I have been friends for some time, but over the last few months we have become very close and are now dating. We thank you for your support and for respecting our privacy. We want to continue our relationship, privately, as an ordinary couple and continue to compete as athletes.”

If he is cheating on Vonn, it would not be the first time. Woods and Nordegren divorced in 2010, after Woods admitted to cheating on her with numerous women.

Nordegren is reportedly dating billionaire coal tycoon, Chris Cline, 53, who is 20 years her senior and owns Foresight Energy in St. Louis, Mo.