Season 6 Edit
Joe first appeared in "One in 8,000" when Donna agrees to help Ron volunteer at the local elementary school. Donna tells Ron to keep her ex away from her, telling Ron that she doesn't like who she becomes when she's around Joe.
While at the school, Joe warmly greets Donna, who rebuffs him. Ron keeps an eye on Joe throughout the day and realizes that he is a genuinely kind and compassionate person. After Joe appears to share Ron's love of woodworking, Ron tells Donna to give Joe a second chance. Donna tells Ron that Joe is too boring for her, to which Ron tells her not to "confuse drama with happiness." Donna asks Joe out at the end of the episode.
Season 7 Edit
The two marry in "Donna and Joe".