It began when early in the series, James was shooting technical free throws, which he missed, prompting Stephenson to make a "choking" gesture at James.
Stephenson actually apologized for the incident, and James tried to downplay any talk of his back-and-forth with Stephenson, saying: "Lance Stephenson? You want a quote about Lance Stephenson? I'm not even going to give him the time. Knock it off."
Though James often downplayed the rivalry, Stephenson gloated about getting into James' head.
"To me, I think it's a sign of weakness," Stephenson of James responding to his antics. "Because he never used to say nothing to me ... Now he's trying to do it to me. So I feel like it's a weakness. I feel like I'm doing something right."
Things didn't cool down once James returned to the Cleveland Cavaliers, however.
Stephenson hopped around the NBA from 2014 to 2017, nearly falling out of the league, but returned to the Pacers at the end of last season and once again found a role.
Surprisingly, James and Stephenson mostly avoided any incidents in the Cavs' first-round sweep of the Pacers last season.
In January, in a Pacers win over the Cavs, James referred to Stephenson as "dirty" after being given a technical foul for shoving Stephenson.
"Lance is just a little dirty, that's all," James said. "I mean, we got history, so I should've known, though. I've know since school that it’s not the guy who tells the joke who gets caught. It's the guy who laughs. So they caught me on the retaliation. He played well."
James once again turned to the high school analogy after the game.
"I mean, I shouldn't have even gotten a tech in the first place," James said. "There's a timeout called and this guy's following me to my bench. I gave him a little nudge and he falls to half court. Come on.
"But I should know better. I should know better. I've been dealing with this since elementary [school]. It's like I tell you a joke, you know, I tell you a joke and you laugh and you get caught. That's what happened. Lance told me a joke, I laughed, teacher caught me, now I've got to go see the principal."