Eva Longoria rocked a red-hot bikini during a beach trip this weekend. The “Desperate Housewives” alum was photographed in Marbella, Spain, on Sunday in cheeky bathing suit bottoms and a matching top. The actress, 51, accessorized with a wide-brimmed hat, sunglasses and a striped cover-up. She took a dip in the ocean and made sand castles in the shallows with her 8-year-old son, Santiago. The self-proclaimed “beach babe” subsequently shared smiling snaps from the sunny outing via Instagram Stories. Longoria, notably, has a residence in Marbella and made headlines last summer for another beach day in an itty-bitty bikini. At the time, she…