Dec. 17 (UPI) -- Anna Kournikova gave a rare glimpse of her twins while celebrating their third birthday.
The 39-year-old former professional tennis player posted new photos of Nicholas and Lucy, her twin son and daughter with her partner, singer Enrique Iglesias, while celebrating their birthday Wednesday.
Kournikova's photo of Nicholas shows the toddler wearing a white polo shirt with blue trim and a blue backward baseball cap.
"3!" Kournikova captioned the post.
The photo of Lucy shows her wearing a blue print top and pants while playing outdoors.
Iglesias commented with a heart emoji on both photos.
Kournikova and Iglesias also have an 11-month-old daughter, Mary. Kournikova shared a photo of the infant in September.
"Wimbledon, here I come..." she captioned the post.
Kournikova and Iglesias largely keep their kids out of the spotlight. Iglesias shared a video in 2018 of himself making Nicholas and Lucy laugh.
Iglesias expressed his love for his children during a concert in March 2018.
"I became a father about 12 weeks ago and I can absolutely tell you two things," he said. "Love my babies! I love them so much."
Iglesias last released the single "Después Que Te Perdí" with Jon Z in March 2019. Latin American boy band CNCO performed its cover of Iglesias' song "Hero" on Good Morning America this week.