All of Lincoln's sisters develop a crush on his new tutor, making it impossible for Lincoln to study.
Lincoln and Clyde are walking home from school, and Lincoln is upset at the fact that he just got an "F" on his latest test. Because of this, Lincoln fears that he will fail the fifth grade. Lincoln realizes that in order to improve his grades, he needs a tutor. At first, he tries to get Lisa to tutor him but Lisa's unable to do so as her tutoring schedule is already filled up. However, still wanting to help her brother, Lisa suggests that Lincoln should get a tutor through the local community college as she claims that students there tutor others to get extra credit for their classes. Lincoln accepts this suggestion and heads off to find a tutor.
Sometime later, Hugh, Lincoln's tutor, arrives. As the two sit down and begin, Lori walks into the room, and inadvertently lays eyes on Hugh. Almost immediately, she swoons over him. Eventually, all the other sisters arrive (with the exception of Lily), and immediately fall head over heels for him. As the sisters and pets (except Geo) begin to crowd around Hugh, Lincoln quickly drags him out.
Lincoln and Hugh try to begin their lessons, but every room they go to the sisters are there, eavesdropping on the two, much to Lincoln's frustration. Eventually, the last place they try to get some progress done is in Charles' doghouse. Unfortunately, the sisters find out about Hugh's location and attempt to enter the doghouse, inadvertently destroying it. Infuriated with his sisters and father, Lincoln calls for a family meeting. Inside the house, Lincoln chews out his sisters and father for their behavior before ordering them to leave him and Hugh alone so that he can prepare for his upcoming test, which they begrudgingly do so.
With the sisters out of the way, Lincoln and Hugh are able to make progress. Hugh discovers that Lincoln is a really smart person, as he's able to know all the answers to his questions. Because of this, Hugh declares that his work here is done, and leaves (by being chased out by Lincoln's madly in love sisters, their British-obsessed father and pets).
The next day, Lincoln comes back from school and is disappointed to learn that he flunked his test again. As Lincoln plops down on the floor in defeat, he unintentionally mentions his substitute teacher's name; Ms. DiMartino. When the sisters hear Lincoln say her name, Luna tells him that Ms. DiMartino is so attractive that all the boys fall head over heels for her. Lincoln explains that Mrs. Johnson broke her leg after riding on a mechanical bull, so she hired a substitute to take cover for her. In a series of flashbacks, Ms. DiMartino's attractive looks made Lincoln lose all of his focus. This makes Lincoln realize that these distractions are what's causing him to repeatedly fail his test. Lisa has the solution: Lincoln simply has to NOT look at her. She proves this correct on Lori by asking her what Bobby's full name is. Lori tries to answer, but Lisa repeatedly shows her the picture of Hugh, causing her to lose her focus and start all over. Lisa then deletes the photo of Hugh, allowing Lori to answer the question without losing her focus. Realizing that it might work, Lincoln heads back to school.
At school, Ms. DiMartino allows Lincoln to retake the test, but this time Lincoln takes the test in his locker to avoid making eye contact with her. After taking the test, Lincoln finally gets an "A". Lincoln believes that he will see Ms. DiMartino in the classroom, so he shields his eyes when he walks in, but to his surprise Mrs. Johnson is back, albeit on a wheelchair.
During gym class, Lincoln is confident that he won't get to see Ms. DiMartino again in another one of his classes. However, it's revealed that Ms. DiMartino will be subbing for Coach Pacowski, whose foot got run over by Mrs. Johnson's wheelchair. Because of this, all the boys immediately get distracted by her attractive looks and run into a pole.
This is the second episode where the title card doesn't have a solid color for a background, with the first being "The Sweet Spot".
According to Lori, Bobby's full name is "Roberto Alejandro Martinez Millan Luis Santiago, Jr.", which means that he is named after his father, or his grandfather on his father's side of the family. This trait is also shared with Lynn Jr and CJ.
This episode reveals the following:
Lola's eyes are blue.
Although being blue, her eyes for the rest of the show are still black.
Lana has a space in Charles' house, provided with a doggie bowl with her name on it.
Lisa tutors Lori (for precalculus), Lynn (for geology), Lucy (for general math), Lola (for biology), and Lily (for finger-painting).
One of Lynn Sr.'s British sayings is "fish and chips", which is a known English dish mostly eaten in the greater part of Europe, such as England.
Innuendo: At one point, Lisa says "Now, if you'll turn around, I'll point out the gluteus maximus." Gluteus maximus is the main muscle in a person's butt.
Study Muffin - The title is a parody of the phrase "stud muffin", a slang term that means a very attractive young man.
Keep Calm and Carry On - On Lisa's desk, there's a poster stick on the right side saying "Keep Calm and Do More Calculus" which is a reference to the infamous motivational poster, which became an Internet meme.
Peanuts - The pencil container on the title card is yellow, and has a black zigzag line going across, just like Charlie Brown's iconic shirt.
Just Dance 3 - The track "Why Oh Why" from Just Dance 3 can be heard in this episode.
When Lori talks on her phone, it is broken, and it has a cracked screen.
Near the end when Lincoln is about to go into the classroom, Clyde is standing behind him, but when he enters the room in the next shot, he is seen from the front, but Clyde has disappeared.
When Lincoln and Clyde approach the classroom, Lincoln's test disappears.
When Lincoln, Clyde, Liam, Zach, and Rusty fall in the trash, Rusty was speaking, but Liam was heard.
In the first part of Lincoln's flashback about him flunking school from falling in love with Ms. DiMartino, one of the lockers (which is presumably Lincoln's) was seen left open, that leaded him getting his face slammed after he fell in love with Ms. DiMartino.
When the sisters are fighting to try to get to Hugh, Lori is holding Luan's ponytail, and her arm is shown to be extremely long.
When the sisters are chasing after Hugh, Lori's eyelashes are missing.
When Lincoln comes home from school after taking his first exam and enters the house with his sisters in the living room, Lori's right arm appears to be gone as she is on her phone.
When Ms. DiMartino hands Lincoln his exam through light face his locker, her left leg is badly drawn.
When Lincoln and Hugh were in Charles' doghouse, Lana was on the left side, but then, she appears with the other sisters and their dad on the right side.
In addition, Luna was missing when the sisters and their dad are seen in the doghouse.
In the Latin American dub, Lincoln speaks to the viewers when he calls for a family meeting, beginning his sentence with "My sisters are unbelievable!", and not "You guys are unbelievable!".
In the Polish dub, Lynn says "Ms. DiMartino" when Lincoln enters the house.
In the Filipino dub, after Lincoln gets an F-mark and a frowny face on the test, Luan says "I know who to call!" instead of "I know just Hugh to call!".
In some scenes, Lincoln's freckles are drawn wrong.
Lincoln's sisters (minus Lily) going bonkers for Hugh, as well as Lincoln and his male schoolmates going bonkers for Ms. DiMartino.
Lincoln's sisters trying to have Hugh nearby asking him to do a task and/or go with them, much to his frustration.
Lincoln separating his sisters (minus Lily), Dad, and the pets (minus Geo) from Hugh whenever they go near him.
A Loud sister making an animal-like sound and another coming in exclaiming which "animal" they have heard.
Lynn Sr. saying stuff in a British accent and looking British whenever he sees Hugh.
Lori doing goose-like sounds whenever something related to Hugh is close to her.
Characters saying "Buh...buh...buh..." when lovestruck.