Throughout their careers, these two A++ singers, one male and one female, hated each other and for good reason. Back when they were on the brink of fame in the late 1930s, he tried to hook up with her with disastrous results. After dining and seeing a show at a nightclub, the married crooner parked his car in the local lover's lane and went in for the kill. He was one step close to sexually assaulting her, after he unsnapped the back of her bra and exposed himself to her. She did the only thing she could… slap him so hard that it left a mark on his face. She slammed the car door shut and yelled at him “I'm not going to be one of those cheap floozies you fuck around with! Your wife will love it that you put the move on a black girl!” Apparently the wife did find out and turned a blind eye like with the rest of his dalliances. The diva was still married (with two kids) to her first husband, but was then separated from him after he went on one too many trips to the bar.
Flash forward several years later and they're both working at the same movie studio.. and on the same movie: an all-star musical extravaganza which they both sang a few numbers in. When the diva first found out that she was going to co-star in the movie with him, she begged the producer to take her off the film not explaining why. Enter the very good female friend of both singers (who also appeared in the film), another A++ list legend, who told the diva to suck it up and ask if she could shoot around her foe. During the filming of this movie, the diva was scheduled to sing at a charity concert with many of the performers from this film, but when she found out he was going to be on the bill with her, she called up her friend to fill in for her and explained to her why she couldn't go on. When friend #1 died a few decades later, she moved her seat at the memorial service so she wouldn't go near her arch enemy.
It also is worth noting that the crooner married another good friend of the diva, an A/B-list actress, and was hammered with phone calls every time he laid a hand on her.