In October 1889, Philippe went to Switzerland to complete a course in military theory. While there he fathered a son, Philippe Debien, by Nina, an actress working in the casino at Lausanne. On his 21st birthday in February 1890 he left Switzerland by train with his friend Honoré d'Albert, 10th duc de Luynes, and entered Paris in violation of the law of exile of 1886. There, he offered to perform his military service, as required by law. Instead he was arrested and confined in the Conciergerie. He was sentenced to two years imprisonment at Clairvaux, but was released after a few months and expelled back to Switzerland.