He might've been a Padawan, but even so, Luke was definitely learning to be resourceful with his power. Wherever possible he used miniature fields to bounce Mao's hands away so Luke could keep his opponent from getting a good hold. He also retaliated with with full force as soon as sand was involved. Luckily there were no direct assaults on his hair or, worse, his glasses, but if Mao was going to sling around wet sand, Luke certainly was too. Like Mao, though, Luke was having too much fun to notice that his ice cream had long floated away, or how terribly cold the water was, or how very dirty they were both getting. He was sure that if... when his parents saw him like this there would be a lot of unpleasant questions, but at the moment he didn't really care. The most important thing right now was to get Mao in a good, strong hold and maybe...
"Alright Mr. MJ impersonator, who has the better ability now?" He was pretty sure that Mao would never in a million years admit to his awesome Force powers being the superior power (as they so obviously were!) but he could at least attempt to get him to say it anyway. "Admit it! Or face a mouthful of sand. Bitch." It was basically an empty threat, but Luke could at least sound convincing about it.