You can do it, but try not to be provocative. For instance, cultivate a leathery chest area. Chain-smoke while you tan. Place a dirty towel over your face. Cough a lot. While you lie on your back, pretend you are an asexual, sand-colored rug. If you feel the need to move, put your top back on. Movement draws attention. Pretend that topless sunbathing is normal in your country. Apply sunblock beforehand. Don’t get drunk. Don’t engage the sunglass or watermelon salesmen. You have a strict business arrangement with your sunbaked chest. Don’t overdo it. Thirty minutes is plenty. Close up shop, buy an ice cream cone, don’t make eye contact. Avoid lounging in the same spot two days in a row. You’re so European.
This brings back of memory from Sweden. I was around 13 and walked onto a beach wearing my swim team Speedo. The looks I got were exactly what a nudist would get appearing on the beach at Nags Head.
Americans are certainly prudes but that can be a good thing sometimes.