One of my favorite tropes in vore, and I don't really know what you specifically call it, is when the pred eats someone's friend.
Like. Observer finds out the pred ate their friend and demands they let them out, but the prey just stifles a burp and says something like "oh, you think they're still solid?"
Or pred eats observers friend and forces them to watch as their friend is turned from a living, begging human being into mush.
Forcing them to trace the path their friend takes, winding around their gut, going deeper and deeper until the tiny bulge they make dissappears in the preds lower abdomen.
And since the observer moved their head so close to the preys crotch trying to reassure their friend they'd rescue them, the pred just might take advantage of them to blow off some steam.......