Singer Enrique Iglesias may be singing the same tune as his legendary Spanish crooner father, Julio Iglesias, "To All The Girls I Loved Before," now that the status of his relationship with former tennis pro, Anna Kournikova is in question.

After almost a decade of dating, the Spanish singer and Russian beauty may be headed for splitsville. 

Acccording to The New York Post's Page Six, sources say that Iglesias and Kournikova's realtionship is "on the rocks" after 12 years.

What could be the problem?

"Anna is getting tired of waiting for him to decide if he wants to marry her or not," a source said. "They've been together for so long, she feels like it's never going to happen. She is ready to move on."

The Huffington Post reported that Iglesias shared his thoughts on marriage in an interview with Parade magazine in March 2012.  "I've never really thought marriage would make a difference. Maybe it's because I come from divorced parents, but I don't think you love someone more because of a piece of paper," he said. "And nowadays, it's not taboo to have kids and not be married. What makes a difference is that you're a good parent, period."

Kournikova spoke about marriage as well. She told Women's Health that marriage isn't important to her, the Huffington Post points out. "I'm in a happy relationship -- that's all that matters," she said. "I believe in commitment. I believe in being open and trusting each other and respecting each other completely."

"This issue has come up before, and they have managed to smooth things over and get back together," a source told Page Six. "Time will tell."

The public has been speculating if Iglesias, 38, and Kournikova, 32,  were going to get hitched, but the rumor was shut down by Iglesias' management team that insisted that they have 'no intention' to marry in the near future, Fox News reported.

Neither the Iglesias or Kournikova camps have commented on the possible split.