This is Ivan we're talking about. Saying "the sun is shining" is just about his amount of obvious, and even then, he may need clarification. But actions he can understand pretty well, and that shoulder nudge tells him enough.

Sorta.

It at least tells him that Gabriel wants to leave as much as Ivan does, so he throws himself at Gabriel. Their shoulders really never stop touching, Ivan just twirls around with him to latch onto his back and away from those deadly fangs.