<Li> Tina Pinciotti (played by Amanda Fuller) was the younger sister of regular Donna Pinciotti . She first appeared in "Eric's Burger Job", but made no appearances following that, except for a brief mention in the episode "Vanstock". A similar situation occurred with unseen Valerie Pinciotti . The two are later written out with no explanation, as demonstrated in the season seven premiere, when Kitty refers to Donna as Bob and Midge's only daughter </Li> <Li> Valerie Pinciotti was the older sister of Donna Pinciotti and Tina Pinciotti, who in "Eric's Birthday" was said to be away at college but never mentioned again . </Li> <Li> Matthew and Rebecca Erdman (played by Kevin Farley and Shannon Holt) were the prudish host parents of Fez . They first appeared in "Drive - In" and convince Fez the rock they detest is diabolical by playing KISS album backwards . Fez's host parents make no further appearances in the show . </Li> <Li> Buddy Morgan (played by Joseph Gordon - Levitt) was introduced in "Eric's Buddy", and was intended to become a recurring character . However, the introduction of homosexual Buddy as a love interest for Eric (at a time when both Eric and Hyde were competing for Donna) did not go over well with audiences, and Buddy was cut from the show . </Li>

Who plays bob's wife on that 70's show