First Aired: March 26, 2006

Plot: After a pregnancy scare, Peter reluctantly agrees to get a vasectomy, but before the surgery, he goes to donate his sperm in case he and Lois want another baby. However, while donating his sperm, he accidentally knocks a large rack of samples over and replaces them himself so that he won’t get in trouble. One of the recipients of his sperm is a lesbian couple, who give birth to Stewie’s half-brother, Bertram, who appeared in the episode “Emission Impossible.”

After the vasectomy, Peter’s sex drive becomes nonexistent. Lois channels her sexual frustration into eating and she becomes fat. Peter ridicules her for the weight gain, but after they inadvertently have sex Peter’s interest is renewed (claiming it to be the hottest sex they’ve had yet) and things heat back up, until her unhealthy eating habits get the best of her. She suffers a heart attack, and during the surgery the doctor removes the fat (to get to her heart) and return her to normal.

Meanwhile, Stewie’s half-brother and archrival Bertram confronts him and they declare an all-out war for control over the playground. A confrontation between Stewie’s stealth fighters and Bertram’s helicopter gunships is inconclusive. Bertram resorts to biological warfare, infecting Stewie with chicken pox.

Stewie infiltrates Bertram’s camp and engages him in a swordfight. Stewie finally prevails, disarming Bertram. Later in the night, Stewie and Christopher Moltisanti suspiciously dig a hole—which is later revealed to be for planting a young tree. Stewie then reveals that Bertram admitted defeat and ran off, to which Moltisanti replied "What a mook!".