Selling, who was known as Caj Lottman in Israel, was born in Stockholm and trained at the Royal Swedish Ballet School. He danced with the Royal Swedish Ballet while still a teenager; he also appeared with the Royal Ballet, American Ballet Theatre, and Australian Ballet.
In the late 1960s, he moved to Israel and helped found the Beit Rothschild dance school and troupe in Haifa. Later, he joined the staff of the Batsheva Dance Company in Tel Aviv, serving as instructor, rehearsal director, and aristic director. In 1984, he returned to Haifa to direct the Beit Rothschild school. Over the years, however, the school lost pupils to the new Haifa Ballet, and it shut down in 2000.