There are no bullies in the house, and how anyone can say that Dexter can't take attacks on him is just an open lie...he has taken all the abuse dished out by Callum, The Twins, Sam, Jackie, Sophie, Sallie and Jemima...have you not watched the ruddy show.?
Dexter has had more insults and abuse than any HM, possibly in the whole history of the show.
Sam is the one who has had an easy ride to date, he's the guy that reacted very badly to hearing a few negative things.