Phil and Mike, having reconciled, sing "Falling Slowly" on karaoke repeatedly, annoying everyone else.
Carol breaks the news to Phil that she's asked Todd to help them conceive by acting as a sperm donor. Phil is slightly uncomfortable with the fact that Carol wants to conceive "the old-fashioned way" instead of via the turkey baster method. Carol brings up Mike for the choice of sperm donor. Phil shoots that idea down. After arguing with himself for a bit, he agrees to allow Carol to conceive with Todd the natural way.
Phil tells Mike that he and Carol are getting divorced so that Carol can marry Todd and conceive a baby. He explains to a confused Mike that it is because he's sterile. Mike is a bit miffed that he wasn't asked. Phil lies that it was Carol who was uncomfortable with the idea and that he (Phil) was all for Mike being the donor. Phil also confesses that he's never told Carol he loves her.
During Carol's very formal wedding on the beach to Todd, Carol and Phil get divorced. Todd gives a speech about how he is honored to have been asked to act as sperm donor during his vows. During the ceremony, Phil interrupts, declaring that Mike should be the one to marry Carol and conceive the child. Mike accepts and marries Carol. Todd is clearly uncomfortable with being passed over.
At the party after the wedding, Todd angrily dances by himself. Phil asks if he is OK and Todd denies that anything is wrong.
Carol and Mike spend the wedding reception getting to know one another and laughing together. Phil sees this and gets nervous, wondering what he's done in getting the two of them together.
The next day, it comes time for Carol and Mike to have sex. Phil buys them outfits for the occasion -- full-body suits that cover all areas of their bodies except for their sexual organs. He also explains to them that he'll be in the room with them during the act.
They go into the intercourse room and Mike reveals he's uncomfortable with Phil watching them so closely. Phil talks Mike into it and Mike reluctantly agrees. Carol and Mike initiate sex, with Phil critiquing and correcting Mike as Mike and Carol role-play picnic sex. The two get more and more into it as Phil gets more nervous. Finally Phil screams out that he loves Carol. She stops having sex with Mike and kisses Phil happily.
The next morning, the group asks Mike about the picnic sex. He explains they didn't go through with it. Todd, meanwhile, has shaved the other half of himself and is harsh with Phil, turning down his offer of a tandem jetski ride (still clearly angry about being passed up as the sperm donor). Gail heads off to start drinking for the day.
Carol enters the room holding what she thinks is an ovulation test and explains she's ovulating, inviting Mike and Phil to go try again. Erica notices that Carol is holding a pregnancy test. Melissa looks at it and realizes that Carol is pregnant. They celebrate happily, with Phil thinking the child is Mike's. Mike explains to Phil that nothing happened the night before, so the baby is definitely Phil's.
Gail sits outside drinking wine out of a straw and suddenly sees a drone hovering above her.