Sibling Rivalry

S4, E22: After a pregnancy scare, Peter reluctantly agrees to get a vasectomy. But after the operation, Peter’s sex drive becomes nonexistent. When Lois packs on some extra pounds, Peter’s interest is renewed and things heat back up in the bedroom until her unhealthy eating habits get the best of her. Meanwhile, Stewie’s half-brother and archrival Beltram confronts him and they declare an all-out war for control over the playground.