Boston Celtics star Jayson Tatum befriended forward Grant Williams when they became teammates in 2019. However, their friendly words get replaced with trash talk whenever they square off against one another.

On Monday night, Tatum and company took on the Charlotte Hornets, Williams' newest team. The ex-Celtic went to the Dallas Mavericks this past offseason, but when that experiment didn't pan out, he was quickly moved to Charlotte at the trade deadline.

This was the first time the C's had seen their former big man in an opposing jersey since January 22, when Boston beat Dallas 119-110 and Williams posted just two points in 18 minutes. He had a much better showing in Charlotte, posting 23 points while going 10 for 16 from the field with seven rebounds and two assists. His effort wasn't enough to stop the league-leading Celtics though, as Boston prevailed 118-104.

Tatum notched 25 points and 10 rebounds in the victory and had a game-high plus-minus rating of +15. Following Boston's 59th win of the season, he joked about what it's like to compete against his former teammate, via NBC Sports Boston.

“Grant always got some s**t to say,” Tatum said. “But, I have to say, that's my brother for life. I don't talk trash at all but if it's somebody I'm close with, like with Grant, I like to have fun out there. It's always good to see him, compete against him. We just had some fun out there.”

The Celtics have definitely had some fun this regular season, as they clinched the No. 1 seed in the Eastern Conference and have a chance to lock up the best overall record in the NBA with a win against the Oklahoma City Thunder on Wednesday. Although the C's can't improve their in-conference seeding, they're not just coasting ahead of the playoffs, per ClutchPoints reporter Jerry Donatien.

“I think last year we were just so antsy to get back to the Finals that we had a few bad losses in the last few weeks of the season and went to six games in the first round—we may have took some things for granted,” Tatum admitted. “This year we've done a really good job of not skipping steps. Respecting every game, every day, just trying to get better.”

Last season, the Celtics went 57-25 before losing in seven games to the Miami Heat in the Eastern Conference Finals. During the 2023-24 campaign, Boston has already surpassed its regular season win total from last season, as it's currently 59-16 overall.

As for the Hornets, they're in 13th place in the East and eliminated from postseason contention. This will be their eighth straight season in which they've failed to earn a playoff berth.

Regardless of the underwhelming season, Williams seemed to enjoy talking trash to Tatum, via Celtics CLNS.

“Him and [Derrick White] constantly call me a hack. I'm always just like y'all are hacks. You just don't get calls for it because you're superstars,” Williams joked. “I always tease him about that because I think he was saying like I was fouling [Porzingis] or something . I was just like, hey man, you fouled [Aleksej Pokusevski] and Brandon [Miller] two possessions in a row. They just didn't call a foul on you because you know, you're light-skinned and you think you're pretty.”

Despite being at opposite ends of the standings, clearly, Tatum and Williams are still having fun with each other.