I love seeing him go on stage to make the audience sing because it's hilarious. Just watch.
and then there's another moment at 3:27 and 4:38
He's so sweet about it but he still laughs...I just
There's also another moment when he let a fan dance next to him during one of his concerts. She was doing this awkward dance move and he was trying to not laugh at her...I can't find the video again but it was just funny to me lol.