Most blackmail plots in comedy follow a very standard formula. Person A finds out that Person B did something bad, and Person B does not want Person C to find out. This usually results in Person A blackmailing Person B, and hilarity ensues. The plot thinkens in a predictable way: Person B has had enough of the blackmail, and comes clean to Person C. Fortunately, this episode of Family Guy deviated from this tired formula, in favour of something else that was more suited to itself.
After catching his father in-law, Carter (Person B) cheating, it did not even occur to Peter (Person A) that he was in a position to do some blackmailing, despite all the years of getting mistreated by Carter. It had to resort to Peter's friends putting the idea into his head to blackmail Carter. As Peter and Carter were moving the television, Peter, without provocation, dropped the terrible secret in front of Babs (Person C). Aside from this incident, what made this episode interesting was that it cast Peter as the straight person, as the dysfunctional Carter tried to cope with the break-up, and the eventual reconciliation between him and his wife.