This is typically the greeting reserved to us by Petey.
And generally, it is used when he wants out of his cage, or some form of attention.
In the case for the former, if we don't let him out quickly enough, the pitch of his "Hi Petey" gets higher and higher...until we do acknowledge him.
But it turns out, he's no longer the only one saying this. This very short sentence of sorts is now part of Léa's repertoire, and, funnily enough, she says the "Petey" part in the very high pitch way Petey does when he really really wants out. It is always very cute when it comes out of him, it was incredibly funny (and still very cute) coming out of Léa - who said it twice this morning.
While she normally mimics my voice when she says her other words, it does seem she's tried to mimic Petey's voice this time around!