That wasn't a girl's voice, making Albus a bit more cautious as he entered, but there was a girl, hiding behind the door. When Albus saw her, he closed the door shut and held out a free hand to greet the pair.
Boyfriend and girlfriend? Just friends? Not that it mattered.
"Hello," he said warmly, nodding to each of them, making eye contact. "I'm Albus and I'll be your mouse catcher today."