Science Movie Day allows Ms. Hoover to fall asleep as her class watches a film that Lisa doesn't fit in the lesson plan. Lisa even goes as far as creating her own lesson plan that would have covered what the students should have been learning.
Nevertheless, what appears to be a quake disrupts Lisa's agenda. The shakes can only be one thing. It's Taco Tuesday!
The students stampede through the hallways and out of the air vents to reach the cafeteria, while Homer and his co-workers sneak in to take advantage of this day.
Lisa observes Bart eating his sixth taco and the lunch lady retaining the salad for another meal. After Lisa questions whether the vegetables will rot or not, the lunch lady tells her that it's genetically modified, so it should last.
While Lisa reads about the effects of eating genetically modified foods in the car, Marge rushes to get to the church before the volunteer sign-up position she wants are gone.
Too late as Marge gets suckered by Ned into giving the sex talk to kids. It's no use, though, when both teenagers at the meeting just go at it in front of Marge.
Afterwards, Lisa presents her argument at the parent teacher meeting at school. Even though Lisa had initially been against genetically modified foods before, she changes sides much to the surprise of her audience.
When a corporation takes interest in Lisa's initiative to drive genetically modified foods home, little does Lisa and her family know that Sideshow Bob is the chief scientist behind it all.
Once Bob recounts how he became a test subject so that monkeys were not injured too much, he tries to rekindle his relationship with the Simpsons. Lisa, especially connects with Bob through their mutual love of Walt Whitman. But, let's not forget, Lisa, that Bob is still a prisoner of the Springfield penitentiary.
Meanwhile, Marge returns to giving her sex talk to teenagers, but this time she prepares with finger puppets. While the teenagers snicker, Marge fails miserably to get her point across about sex.
Elsewhere, Lisa enjoys Bob's company despite Homer's usage of the Bunsen burner to toast the rest of the marshmallows since he already ate all the chocolates.
At home, Homer tries to squeeze in some alone time with Marge, yet an angry Marge decides to use Homer as an example for her sex education class.
Marge brings Homer to church to tell her class that she has abstained from sex with her partner for two days. The mere image of Homer and Marge touching each other gives the teenagers enough reason to pledge to wait until marriage for sex.
Lisa, on the other hand, is having a blast with Bob at the museum. Despite having to carry his ankle block from prison, Bob enjoys his time with Lisa.
When Lisa passes through an exhibit, a heavy display model comes close in squashing Lisa, but Bob saves the day.
Inquiring minds want to know. How did Bob have the strength to prevent the sheet metal from crushing Lisa?
That's when Bob reveals to Lisa that with the success of genetically modified foods, he has been able to change his own DNA.
Bob also tells Lisa that the real reason behind their trip to the museum is because of his plans on using the DNA of the geniuses in the exhibit to become the smartest of them all.
Bart comes to Lisa's rescue with Bob going cuckoo after a family incessantly asks him to take a picture of them multiple times.
As Bob chases Bart and Lisa down, teenagers from Marge's sex education class are stealing finger puppets.
With his grasshopper legs, Bob catches up to Bart and Lisa, but Marge somewhat saves the day with her sex education class. One by one each sexualized teen tries to tackle Bob. Who will win in this cesspool of teens versus villain?
Tune into The Simpsons every Sunday at 8 p.m. on Fox.
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