The 35-year-old retired tennis star shared a rare photo with the 41-year-old singer on Instagram. The longtime couple were all smiles as they posed with Kournikova's half-brother, Allan Kournikova.
Kournikova, who celebrated her birthday Tuesday, captioned the snapshot with heart, kissy face and balloon emojis. The former tennis pro had shared a clip of herself dancing to Iglesias' song "Duele el Corazon" in May.
Kournikova and Iglesias have been an on-again, off-again couple since 2001. The tennis star appears to be wearing a large gold wedding ring in several posts despite the pair's previous ambivalence toward marriage.
"I'm not against marriage, not at all, but when you've been with someone for such a long time, I don't think it's going to bring us any closer together," Iglesias told CBS This Morning in 2014. "I do not think it's going to make us any happier."
"We are extremely happy the way we are," he later clarified on the Today show. "I'm not against marriage by any means. I have not ruled it out, but if you're happy, I don't think [marriage] will really make a difference."
Kournikova herself once told Woman's Health having a "happy relationship" is more important than marriage. The tennis star also revealed in the interview she "absolutely" wants to have children someday.