Watch: Marcus Smart and Joel Embiid's flop-off is the NBA season's first 'altercation'

Embiid hooked Smart's arm while securing a rebound, and Smart flopped to the ground. Smart then grabbed Embiid's leg as he walked away, and Embiid "slipped" and fell to the ground. Before it could become anything more than a matchup between two pre-eminent flop artists, James Harden stepped in as a peacemaker. Smart was assessed a foul and a technical, and viewers at home were treated to another extensive video review.

The two players have history. During a playoff game in 2018, Embiid caught Smart in a very sensitive area with the follow through on his jump shot.

In 2019, Smart was ejected from a Sixers-Celtics game after shoving Embiid to the ground when his back was turned.

Their beef actually goes all the way back to college, when Embiid's Kansas team beat Smart's Oklahoma State team. Embiid posted this mocking caption on Instagram:

Embiid wrote: "Not very SMART to jump on that one."

And there you have it. Playoff games, flopping, kicking, and shoving can all make players dislike each other, but nothing fuels a bitter rivalry quite like a terrible pun.