As long as there was no chocolate syrup or anything, he will be fine. My dad let my childhood cat drink coffee every morning and that cat lived to be 17.
They’ll be fine. But to be a responsible owner, offer them a cigarette
on the real: caffeine can be toxic but you say it was a cup and not grounds? And a few licks? Should be ok
So no chocolate syrups but the beans do have a chocolate flavoring... granted, it was brewed. Don’t think it’ll do much harm, might just be energetic for a while
Dogs are basically trash compactors. Sure large amounts of chocolate, onions, or grapes could hurt them, but otherwise they'll be fine. Hell I've had dogs eat an entire box of chocolate frosted donuts with no ill effects.