The pair met during the taping of "Surreal Life 4" and their relationship is reportedly going strong a year later, VH1 said in a news release.
The couple is featured in "My Fair Brady," a takeoff on the name that made Knight famous in the 1970s as member of TV's "The Brady Bunch" clan. "My Fair Brady" kicks off Sept. 11 on the cable music network.
Knight's TV mom, Florence Henderson, will make a guest appearance as he grapples with whether to marry his "America's Next Top Model" girlfriend, who is 25 years his junior.
Celebrity Breakups and divorces of 2014 [PHOTOS]