Neil knows how to dance bc his mom put him in dance lessons ever since he was 4 up untill age 11 (I headcanon that Neil is 11). So when max and Neil are alone (probably skipping dinner or activies) Neil often makes max dance with him.

He puts on music and twirls max alot. Max doesn't mind it and is usually blushing a light red when he does this.

Neil doesn't like dancing that much but he genuinely enjoys it when he's doing it with max.

They usually do this when they skip dinner or night activities because they like dancing when it's dark out more.

They made this their little secret and nobody knows about it.

Yet.