Season 1: Episode 5: Father-in-Law
Kim's and Christine's father, Don Ludke, comes for a surprise visit. Greg feels left out as Don has never liked him -- and still doesn't. When Greg's attempts to win him over fail, Christine tells him the real reason her father doesn't like him is because he doesn't respect people who can't do things around the house. Greg changes his plans to buy a jungle gym for the kids after Don says that only an idiot would buy a pre-built jungle gym when he can build his own and save money. In an effort to impress him, Greg tries to build his own jungle gym, but it falls on top of him while he's working on it. After Greg says to Kim that he doesn't want Don in his house again, Jimmy tells him that the way to get on Don's good side is to make him feel smart without intimidating him, like he's wont to do. Following that advice, Greg extends the olive branch to Don, and asks for his help with the gym. Afterwards, he starts to have a heart-to-heart talk with Don in regards to the way he's treated, only to wind up violently attacked by the man.