The blondies are big fans of their baby brother, at the moment. Because he does absolutely nothing, other than monopolize parental attention every once in a while.
They beg to hold him and clamor to touch his little face.
If he’s hanging out in the stuffed armchair, they’ll run over and climb on (trample him) so they can ‘play’ with him.
But they lose interest after 0.9 seconds. And tend to forget that he doesn’t have the same gross motor skills as they do.