Is there some secret to not have subjects in photos spazz the hell out?

By spazz out, I mean super hyper and strange gestures from simple photos. I've been trying to animate pics of my wife and I when we were younger, super simple stuff like selfies or like one of us snapping a full body shot of the other in front of of a tourist landmark but it is a constant struggle to keep either of us contained from acting totally insane.

I started using Grok last month out of convenience since I don't always feel like sitting at my computer using Wan but the frustration doesn't feel worth the effort anymore. Best I can think of is "no talking," or "keep face exactly the same," to avoid chattiness and extreme facial morphing but I just can't tame the bizarro movements. Am I missing something in prompts or wasting my time?