S3, E3: Panic breaks out when the Critch house’s plumbing gets backed up one morning. It turns out their septic tank is full, and there’s only one thing to do – call in Mary’s dad. And so, as Mike Sr prepares to endure the presence of his emasculating father-in-law, Mark is faced with his own discomfort – heading to school with a full bladder. Once Mark arrives at St. Bridget’s, relief is not an option as an act of bathroom vandalism results in the facilities being off-limits and ending in a tense interrogation by a Nun who is judge, jury, and executioner. Meanwhile, Mike Sr and Pop deal with friction from Mary’s dad while he clears their clogged plumbing. He fires barbs at Mike Sr, insinuating that he’s not good enough for his little girl, and at Pop for sharing a room with a child. Finally, the family’s septic tank is cleared, grievances are aired, and mercifully, bladders are emptied.