Bobby Orr/Phil Esposito in Boston
Never heard that. And I've read Phil Esposito's book "Thunder and Lightning". The worst thing he says about Orr in it is that they disagreed with Alan Eagleson prior to everyone finding out he was a fink. So I guess they clashed on that, but that's it. Other than that, he says they went to bars together and such. Bobby was younger and likely more carefree as well (although Phil was the champion philanderer). Phil is brutally honest in his book about everything. You would think he'd be honest if him and Orr hated each other so I doubt it.
When Esposito was traded it was Don Cherry and a depressed Orr that broke him the news in the middle of the night. Doesn't sound like a teammate who hates the other to me.
I'm also not sure if fighting in team practice would constitute anything. Emotions get high, players are like family, they fight, sometimes the media makes a big deal out of it. In the end the players might have even more respect for each other. In the media you don't hear how the players probably went for a beer after practice.
But here's a few that were out in the open:
Barnaby/Jagr - Jagr once told the media he had seen Barnaby in the shower and felt sorry for his wife
Avery/Dallas Stars - When Turco and Modano who are well respected come out to bash you, I think you are doing something wrong