Given the chance to think on it, Loki --- the original, Jötunn version, as opposed to the large feline --- would have understood that Vali can take care of himself, and that this sort of beast probably poses little threat. But if parents thought too hard on their protective instincts, few would have the chance to step between danger and their grandchildren.
So when Vali touches his shoulder, he isn’t precisely fight-ready --- just wary, and acting on instinct. Which leaves space for him to glance behind him and blink in confusion, open his mouth, look back to the lion in mild bafflement, and frown.
The cat, for its part, seems to understand that it is outmatched --- or, as Vali guessed, simply isn’t interested in what would probably be a rather stringy meal. It slinks back into the undergrowth, footsteps silent over the blanket of pine needles and decaying leaves, and vanishes as though made of vapor --- leaving father and son standing alone on the path.
“ ... Loki ? ” is all the father manages to say. His brow furrows, and he licks his lips. “ You gave that creature my name. ”