The happy couple, who recently celebrated their one-month wedding anniversary, stayed close to one another while splashing around in the water and embracing.
The former Desperate Housewives star also took to Instagram to document her celebrity run-in whilst in Ibiza: Cristiano Ronaldo!
"Oh hello @cristiano #NoBigDeal #EuropeCupChampion #Portugal," she captioned a pic of the two posing with Bastón and a few other friends.
Longoria and media mogul Bastón, 48, tied the knot with a fairy tale wedding in Mexico in May. The two have been together since 2013, and Bastón popped the question with a ruby and diamond engagement ring in Dubai in December.
"There were so many memorable moments," Longoria recently told reporters of the wedding. "Then the tequila kind of blurred it all! But he surprised me throughout the night – a surprise singer, a surprise video, a surprise this. So every half hour there was another surprise that I was like, 'I can’t handle any more! My heart is going to explode!' "
"It was actually a really small wedding," added the actress. "It looked huge on social media because everyone was posting, but it was actually like 80 people. Super small."