This time, in Luton, two-year-old Sebastian is literally banging his head against the wall in frustration. This toddler will also hit, bite and kick to get his parents' attention. Mum and dad feel powerless to control him. Kathryn finds out that Livia and Paul had a long and difficult journey to start a family. She needs to get mum and dad to stop wrapping their son in cotton wool. Easier said than done.