Both Leonard and Sheldon’s mothers are coming to visit to see their sons receive an award for the ground breaking paper which has driven so many of the story lines this season. Leonard isn’t concerned about his mother’s visit, at least not to the extent about caring when she is arriving at the airport since her arrival over California will cause a disturbance in the Force. In case anyone needs reminding, Leonard reminds the room that his mother is not his number one fan and may, in fact, not even know what the word supportive means. Sheldon, helpfully, points out that he has had a lifetime of nurturing and support from his mother, even when her religious point of view was at odds with his scientific exploration of the world to the extent that couldn’t understand him. Sheldon is busy arranging a bouquet of yellow roses for his mother, leading Amy to grump that when she asks for flowers, he explains that they are merely a bunch of severed planet genitals. Amy explains that a mushroom log really isn’t the same as flowers. Penny, aware that Leonard’s mom doesn’t like her suggests that she can run out and get 
something for her. Leonard thinks the only thing that might work is a Ph.D., but Penny points out it didn’t work for Leonard. And apparently, this will be the first time the two mothers will have met each other in the several years that Leonard and Sheldon have lived together.
Sheldon’s mother, Mary, arrives first. She’s proud of her son and Leonard for getting the award even if she couldn’t understand it when she read it. Sheldon explains that the idea behind the paper is straight-forward and tells her what the paper is about. Mary doesn’t understand how he can believe the scientific mumbo jumbo when he can’t believe in Noah’s ark, clearly misunderstanding the difference between believe/faith and evidence/proof, although, of course Sheldon and Leonard’s paper is a theory which has not yet been proven or disproven, but merely offers up a model for explaining the universe. Instead of trying to explain how science works, Sheldon merely asks his mother what the lions ate on Noah’s Ark. Sheldon asks his 
mother to refrain from discussing the Bible in front of Leonard’s mother because, while he loves his mother and isn’t embarrassed by her, he is embarrassed by the things she thinks, does, and says, and interesting reversal of the “Love the sinner, hate the sin” mantra.
Walking up the stairs, Leonard’s mother, Beverly, asks if he and Penny have set a wedding date, only to be told that they are taking it slow. Given Leonard’s history with Penny, his mother questions the health of their relationship, starting by ask about their sex life. When he responds it is satisfactory, she asks why it is only satisfactory, never willing to show him any sort of support. When Leonard revises his answer to tell her that they have a wonderful sex life, she wonders why he feels the need to impress his mother with his sexual prowess, the problem clearly being less Oedipal and more an issue with Beverly. When Leonard asks his mother to lay off the psychiatry in front of Mary, Beverly questions whether he is attracted to Mary, but agrees that she will act like an adult around Sheldon’s mother.
Entering the apartment, Beverly greets Sheldon and congratulates him on the paper, noting how brilliant she thought it was. Leonard asks why she didn’t think to mention that to him during their two hours car ride from the airport and she explained that it’s a mother’s job to make sure her children are not overly dependent on a parent’s (or anyone’s) approval. When Mary bring up the idea that God may have been watching over her plane during the flight, Beverly just looks at her incredulously.
Despite this rocky start, Mary and Beverly are chatting in the living room. When Mary comments about how proud Beverly must be of her son, Beverly responded by talking about how he has just argued a case in front of the Supreme Court, before realizing that Mary was referring to Leonard, which raises the question of whether Beverly treats Michael, her other son, the same way she treats Leonard when she’s with him, or if she shows pride in Leonard when she isn’t with him (Michael’s name was revealed in the second season episode “The Maternal Capacitance”). Sheldon shares a map showing their hypothesis with Beverly, but when Leonard reminds her that it was his hypothesis initially, she shushes him and asks Mary when she first realized how extraordinary Sheldon’s mind was. Sheldon, with any of Leonard’s self-esteem problems, prods his mother to tell stories about him, and she regales Beverly with the story of the time he tried to build a nuclear reactor in the tool shed (first described in the first season episode “The Luminous Fish Effect”). Mary’s version of the story clearly indicates that she has a strange view of Sheldon, who, of course, is jumping up and down to hear a story about himself, like a four-year-old. Leonard suggests that his mother tells a story about him making a Van De Graaff generator out of a vacuum cleaner, which gets translated into “He broke the vacuum cleaner.”
Sheldon elects to share photos of himself with Beverly, who demonstrates more interest in them than she ever has in anything Leonard has done, and Leonard sits, sulking, at the end of the couch. Penny comes in and greets Beverly with a hug, which she does not reciprocate, although Mary does. Penny shows Beverly her ring and when Beverly comments on the cost, Sheldon reveals that Leonard bought it on-line that repurposes diamond drill bits as rings. Leonard pulls Sheldon aside to talk to him not only about his ring revelation, but also to complain that Sheldon is hogging all the attention from both mothers, making Leonard feel even more isolated than he normally would during one of his mother’s visits. Leonard compares him to an elephant seal pup who nurses from two mothers. Sheldon reverses the viewpoint saying it is more like two mother seals trying to nourish the same pup, and he’s more accurate than Leonard in his portrayed of what is happening. While his description for it as a double mother suckler, may not be entirely accurate, Leonard agrees that it, or something quite similar, does apply.
In the living room, Penny explains they’ll set a date for the wedding when the time is right, only to be told by Mary that they were married the first time they laid together, eliciting a derisive snort from Beverly. When called on her dismissive attitude, Beverly doubles down, pointing out that she does realize how important Mary’s superstitions are to her. Mary points out that she’s read Beverly’s books and her Freudian psychology is just as much superstition as anything Mary might believe. Penny, caught in the middle of it, tries to make light of the situation by pointing out that they both believe in bearded Jewish guys. She quickly accepts Mary’s advice to stay out of the discussion. Mary, of course, is as dismissive of Beverly’s field of research as Beverly is of Mary’s religion. As Penny tries to steer the conversation to something safe, Sheldon and Leonard return to the room, arguing about whether Beverly likes Sheldon more than she likes Leonard. The question isn’t whether she does like Sheldon better, but if there is anyone she doesn’t like more than she likes Leonard.
Beverly and Sheldon have found their way to a coffee shop, escaping from Leonard and Mary. Beverly expresses regret at upsetting Mary, but Sheldon reassures her that Mary will forgive her so she won’t wind up in Hell. Beverly notices that Mary’s parenting style is diametrically opposed to her own methodology. Sheldon notes that Beverly’s technique is a proven way to raise children and train rats. Sheldon turned out well despite his mother. Sheldon points out that Leonard’s siblings are successful while his own siblings are idiots.
Mary, on the other hand, begins showing support for Leonard and Penny. She also notes that she needs to apologize when Beverly gets back, splitting the difference between being a good Christian and turning the other cheek and being a good Texan and shooting her. Mary offers them spaghetti and hotdogs, Sheldon’s comfort food. While Sheldon is always up for it since Mary made it for him whenever he wanted, Leonard doesn’t feel that he has deserved it.
Mary and Beverly shake hands and agree to respect each others’ beliefs (or at least pray for the other one) and Leonard wants to get Beverly to her hotel before they start up again. Before they go, though, Beverly tells Leonard that she realizes that there is more than one way to raise a child and she wants to try to shower him with unconditional love. When he asks when that will start, she dismissing him as needy, but offers him an uncomfortable hug.
In the B storyline, Bernadette walks into the kitchen in the Wolowitz house to find their permanent houseguest, Stuart, standing in the kitchen in his underwear. She lays down ground rules about how he should be dressed, which is undercut by Howard’s entrance, also undressed.
Later, Howard, still in his underwear, is playing video games with Raj while Stuart, now dressed looks on. They are also having an important discussion of how vampires have given way to zombies in popular culture and speculating one what will come next (Invisible Men, according to Raj). Bernadette enters to find the three men-children relaxing in her living room while she was running errands. The only one who can actually claim to have accomplished anything was Stuart, who put on pants. Bernadette informs them that they have to clean the kitchen. When Raj complains that he doesn’t live at the house, Bernadette challenges him. He doesn’t have to clean if he can honestly say that he doesn’t have any laundry at their house.
The three boys are cleaning the kitchen when Raj asks how old some Jell-O is. Since the Jell-O is actually carrots, Stuart assumes it is quite old (although it wasn’t that long ago that they had to clean everything out of the refrigerator following the power outage in “The Leftover Thermalization”). While they clean the room, Raj and Stuart raise the fact that Bernadette’s relationship with Howard is similar to the relationship he had with his mother, which isn’t healthy. Howard argues with them, but only reinforces their argument. He realizes he must act like an adult and goes to take out the trash, resulting in garbage spilling over the floor and Howard calling for Bernadette’s help.
Although the floor looks clean after the massive garbage spill, when Bernadette comes in, first Howard’s shoe and then his sock stick to the floor, demonstrating a less than stellar cleaning experience.
The final scene shows Raj, Howard, and Stuart scrubbing, sweeping, and scouring. Raj starts whistling “Hard Knock Life” from Annie. Bernadette walks in, unseen, and rolls her eyes as she immediately leaves to the boys to continue singing.
This episode is atypical of most with a Geek factor approaching zero (the Geekiest part of the show are the boys playing video games and singing a song from Annie), but it also is an interesting character study of two characters who are practically caricatures. Mary is a religious fanatic in a rational world. While Howard is cultural Jewish and Raj tries to hide his beliefs, Mary fully believes in her version of Christianity and tries to live up to its standards, not always failing, and aware of her failures. Beverly, on the other hand, is a theoretical psychiatrist who doesn’t understand, or even seem to like, people. The focus on the episode on their characters and interaction, partly with each other, but mostly on their parenting style, makes for an intriguing show which actually tackles an issue in more depth than usual. And given Beverly’s almost total lack of maternal instinct, it is important to note that the three episodes in which she actually visits Leonard all include the word “Maternal” in their title.
