Chip and Joanna Gaines have finished shooting the fifth and final season of their hugely popular Fixer Upper series on HGTV, and one thing is clear about their future: It will include diapers. The reality stars announced on Instagram that baby No. 5 is on the way, reports People. Their first four kids range in age from 7 to 12, and Chip, 43, suggested that No. 5 wasn't exactly planned. In a tweet, he explained that he and Joanna, 39, went to see the duo Johnnyswim in concert a few months ago, and "one thing led to another" after the "too romantic" concert. (More Fixer Upper stories.)