Asklemmy

What the fuck? I was like dead certain that you were stuck with a bunch of high schoolers at a grocery store or something. That should never be happening anywhere remotely close to a cube farm.

Best strategy is to play dumb. "Hello, [fuckface's manager], I have some concerns about the tiktok content [fuckface] is making for the company and some questions about my job responsibilities in relation to it. [Fuckface] pretty regularly interrupts my work to request me to act in these videos and it is getting in the way of my usual duties. If my participation is required, could you please let me know in writing? I'll also need to discuss with my manager about how this should be prioritized and scheduled alongside my other job duties."

Force their awareness in a way that doesn't immediately look like an assassination. The more you can get in writing the more rope this guy makes to hang himself with. If somehow they claim it's actually work related, keep pushing the edges of "I just want to be sure" until his channel is company property or he shoots himself in the foot.

Alternatively, get paid to intentionally do bad acting. "Oh, I've never been good on camera, sorry!"