Eva Longoria Heats Up the Beach in Black String Bikini

Eva Longoria kicked off her weekend early ... sunning her buns in a teeny tiny black swimsuit in Marbella, Spain on Friday!

Check out the gallery of sizzling pics -- Eva flaunts her toned physique in a revealing string bikini as she takes a stroll along the beach. She appeared to dip in all the way, as exemplified by the water glistening across her smooth skin and her wet hair slicked back into a ponytail.

Eva has been embracing the beach life all summer long -- just a few weeks ago, we spotted her rocking a blue bikini in Marbella while spending time with her husband José Bastón -- who she kissed at one point during their day under the Spanish sun.

And just before that, she showed off her tanned curves in a bright orange two-piece.

Earlier in July, she had some gal pal time with Christina Milian in Spain ... and it's a surprise the stars didn't shut the whole beach down by being too hot!