Backstreet Boys surprised their fans this week by bringing their kids onstage with them. Nick Carter walked out with two of his three children – son Odin, 6, and 2-year-old daughter Saorise. The other band members also brought out their “Backstreet Babies.” AJ McLean was joined by daughters – Ava, 9, and Lyric, 5. Howie Dorough’s sons – James, 13, and Holden age 9. Kevin Richardson’s two sons were also…