Rob Estes will be joining the cast of The CW’s 90120. The one-time Melrose Place star is stepping into the role of Harry Mills, husband to Lori Loughlin’s character, Celia Mills. Harry signs on as the principal of West Beverly High, his alma mater, after he moves his family from Kansas back to Beverly Hills to take care of his aging alcoholic mother, Tabitha, played by actress Jessica Walter.