The sister of Boston Celtics big man Al Horford just dropped a truth bomb all over Giannis Antetokounmpo and the Milwaukee Bucks. Anna Horford's brother, Al, was involved in a bit of an altercation with the former back-to-back MVP during Monday's Game 4 showdown, and apparently, there was a particular moment in the game that really got on Al Horford's nerve.

Anna took to Twitter after the game to share the exact moment that triggered her brother. As it turns out, the Celtics veteran got ā€œpissedā€ with how Giannis decided to stare him down after throwing down a poster all over Horford:

Anna is speaking from experience here and I'm pretty sure she's seen that look from her brother more than a few times growing up. The moment she saw it on Monday night, Anna knew the Bucks were screwed.

True enough, Al Horford turned back the clock for the Celtics, finishing with a team-high 30 points (tied with Jayson Tatum) on 11-of-24 shooting, to go along with 13 rebounds, five assists, and three triples. Horford was integral for Boston as they escaped with a 116-108 victory to tie this series up at 2-2.

Maybe Giannis and Co. will think twice the next time they try antagonizing Al Horford?