Well, it seems this big sis wasn't having any of it!
Koko took to Twitter on Monday with a very cryptic message about all the "sh*t", writing:
[Image via Instagram.]
We can only assume he's playing a dashing young John F. Kennedy… or at least one of his equally handsome brothers!
The flick also stars Marcia Gay Harden, Paul Giamatti, Billy Bob Thornton and Jacki Weaver!
Parkland will be written and directed by journalist/novelist Peter Landesman and is being produced by Tom Hanks' company, Playtone.
It's so exciting to witness Zac's transition from tween musical heartthrob to legit, oscar-track film actor, and we must say…
You still look MIGHTY sexy when you're being oh so serious, Zac!
[Image via Retna LTD.]