6. He Can Sing Nursery Rhymes
It's sort of silly and yet adorable to think that your boyfriend, who plays video games and basketball, can actually sing "Baa Baa Black Sheep" and "Mary Had a Little Lamb." But if you find him in the company of children, singing along to happy tunes, you have yourself a potential doting father.
If he doesn't, don't worry.
Nursery rhymes are pretty much about rhyme and rhythm so they're not hard to learn.