Stan is spying on his neighbor, Chuck White, desperate to beat him to church for once. Chuck gets a good start, so Stan races to the church like a madman. But Chuck still beats him to the shady parking spot. At church, the deacon chokes on a communion wafer. When Chuck volunteers to be the next deacon, Stan also volunteers. An election is necessary.
That night, Francine makes potato salad for the deacon's wake. But when Roger eats it all by mistake, he has to whip up a new batch. At the wake, the potato salad is such a hit, everybody supports Stan for deacon. Francine is confused. The potato salad had a secret ingredient she didn't put in. Later, Roger explains that he's going through his reproductive cycle and he accidentally lactated into the potato salad when he was making it.
Worried about the secret getting out, Stan enlists Karl Rove to run his campaign. Rove suggests serving as much potato salad as possible. Stan milks Roger to get more of the secret sauce. Meanwhile, Steve is trying to cozy up to Betsy, Chuck White's gymnast daughter. At a church event, Stan runs out of potato salad. His supporters immediately disappear. Rove orders Stan to never make that mistake again. Betsy's mom, meanwhile, has banned her from ever seeing Steve again after catching Steve and Betsy holding hands.
After Klaus tells Stan that Roger lactates more after eating, Stan hooks Roger up to a homemade contraption that continually feeds and milks him. But it breaks under the weight. Steve gives Roger CPR to make sure he's okay. The next day, Stan wins the election. Roger's feeling better, his reproductive cycle over. And Steve…finds out that he's pregnant. Roger thinks Steve sucked out his egg during CPR. Stan has to keep this secret from the parish. But Francine advises Stan to be a father to his son.
Stan rents a camper and takes the family down to Mexico to get Steve a certain surgical procedure. But when Steve says he'll have the procedure so his dad can beat Chuck White, Stan thinks he's a terrible person and tells Steve to keep the baby. Back at home, Betsy climbs a tree so she can kiss Steve through the window. The next Sunday, Stan resigns his deaconship. Meanwhile, Steve finds that he's no longer pregnant. Roger asks who he's been kissing now. Steve runs outside to find a pregnant Betsy being shoved into a cab by her disappointed parents.