Haley's 21st Birthday - S6-E10
Plot hole: The family mistakenly believes Hayley will be having her first drink. However, there were several instances in earlier episodes where they saw her drinking or drunk, or she admitted she'd been drinking. For example, in the episode "Arrested", the family drove down to bail her out of jail for underage drinking, and they saw the video footage, and the family members who didn't go were informed of the situation.
Plot hole: Luke says they received a red light ticket in the mail from the time he stole a car, but it was Cameron's car he stole. (00:21:25)
Answer: Mitch is upset that his dad doesn't seem to support his getting married. When they talk about Jay's friends not coming to the wedding, Jay makes it seem like Mitch wouldn't want them to come anyways. Mitch sees it as it's actually that Jay doesn't want to invite his friends to his gay son's wedding because he's embarrassed and uncomfortable about having a gay son. Essentially Mitch sees it as if he was marrying a woman, Jay would be willing so spend money on the wedding, host it at the club, and invite all his friends to it.
Bishop73