After his last disastrous social outing, Kurt had learned that alcohol was his friend and so he imbibed copiously once he was on the yacht. Kurt was well aware of the strange dichotomy of his personality. A shy performer. In a group of normal people he was reserved, but on stage he was transformed. Cheerful, ebullient, charming; a genuine showman. Drinking made him feel like he was on stage.
The ladies on the yacht seemed fascinated by him (he didn't seem to realize they were paid to), and once he was feeling especially outgoing he began doing acrobatics for a delighted crowd on the upper deck. They probably thought he was part of the entertainment, but he didn't mind. When he tired of that he wandered and mingled and drank some more.
Eventually he ran into Pietro who he greeted brightly with, "Guten tag, Pietro!" Somewhere throughout the day he'd lost his shirt, but gained a red scarf that he'd tied over his head like a bandana. He wished he had his rapiers. They were on a boat, he could live out his pirate dreams. Act out scenes from his favorite swashbucklers. He battled for a moment with an invisible foe until the beer he clutched with his tail spilled over and reminded him of his audience. He turned back to Pietro. "This is a very good party, mein freund."