This is really adorable; Hugh tweeted:
James McAvoy shared this incredible song with me. Love it! Hope you do too. http://bit.ly/15fsbkp
They are both dads who love their little families, so I can see James and Hugh sharing not only songs but cute stories about their kids.
Also it's interesting, and poignant, to see the differences between them - Hugh's father means everything to him, James is estranged from his father who he hasn't seen since he was seven. Guess it made him even more determined to be a great dad.