Anna Kournikova Celebrates Twins Lucy and Nicholas' 4th Birthday with Sweet Tributes: Photos

Anna Kournikova is showing her little ones some love on their birthday.

On Thursday, the former tennis pro, 40, shared sweet tributes on Instagram for her twins Lucy and Nicholas, whom she shares with Enrique Iglesias, as they celebrated their fourth birthday.

Kournikova honored Lucy and Nicholas each with their own post, simply captioning both of the sets of photos, "4!❤️"

The athlete featured some adorable shots of the preschoolers for their special day, including a cute picture of Lucy on a playground and a snap of Nicholas wearing a Mickey Mouse shirt and looking directly at the camera.

Iglesias commented with a string of heart emojis on both of the posts for his kids. The longtime couple is also parents to their 21-month-old daughter Mary.

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The 46-year-old singer recently appeared on an episode of SiriusXM's The Jess Cagle Show where he discussed the moment his children watched the steamy "Escape" music video featuring him and Kournikova.

"I think my kids have already seen — well, I think, no, I know my kids have already seen that video," he said. "And they're putting two and two together. Like, 'Oh, really?' "

Iglesias and Kournikova first met when she starred in his 2001 music video for "Escape," which shows the duo making out and getting handsy on a bathroom sink and in a car. Sparks flew on set and the singer and former tennis pro began dating shortly after.

"Whenever they hear one of my songs they can actually recognize my voice, which is pretty cool. But when they watch that video, I think it does throw them off a little bit," Iglesias recalled on the show. " 'What is Mom doing there?' you know, 'with Dad' you know? 'When was this?' It's actually incredible to watch the expression on their faces. It's pretty cool."