When Desi Arnaz first set eyes on Lucille Ball in the commissary of RKO Pictures in Hollywood in early 1940, it was not an auspicious beginning to their relationship. The Cuban bandleader-turned-fledgling actor made a derogatory remark about the then-B-movie actress’ appearance. “He wasn’t impressed at all, calling her a ’10-cent whore,’ a ‘p–a’ — the Spanish word for prostitute,” author Darwin Porter told The Post, noting that the 28-year-old Ball, five years older than Arnaz, was dressed for a role as a cheap burlesque dancer in the film “Dance, Girl, Dance” with Maureen O’Hara.