Well the song which Bert is singing in these photos just goes Hugs are fun. It's a Yo Gabba Gabba song, though I'm not sure if they say "hugs are fun" Though they often put new words to their tunes, this tune as one of his favorite songs "I like fish") But in this case he shows that he likes Lola at least as much as fish. Hugs seem to inevitably end in a tumble over. About even ods on which child lands on top, and shockingly no injuries. Bertram tried to hug Milo too, but he just wasn't interested.