The beginning of one episode where Jenny has just finished telling the boys how babies are made, leaving them with horrified expressions. That is all.
Watch the backgrounds in a few episodes.
"Puppet Bride" - Little Acorn talks about how all the other puppets have a life partner: Punch has Judy. Erthas Bernie...
"The Boy Who Cried Robot" - "The dike! She is about to blow!" In this case (and with that spelling), "dike" refers to a dam, not a lesbian (the homophone that is a derogatory term for a lesbian is spelled "d-y-k-e").
Not to mention the recurring biker chicks with a dom/sub theme. Or Jenny's speaker system that comes out of her chest....OK, let's just say this whole show as a whole can be Getting Crap Past the Radar.
In one episode, Jenny is expelled and has to be home-schooled. Dr Wakeman sets up a fake prom, and pairs Jenny up with XJ-8, her sister.
In one episode she has to keep saving the world during school, and since she already used I have to go to the bathroom, she leaves a blow-up doll of herself in her chair. She comes back and lets the balloon blow off - and it zooms into Sheldon's desk, who closes it with a smile...It's a robot blow up doll. He's just creepy.
Sheldon: Nice set...of wheels.
In "Mind Over Matter", when Jenny has difficulty fighting an opponent:
Jenny: No time, Mom! I'll just download some new upgrades from the Internet!
How about when Ms. Wakemen takes off her coat. It cuts to a between-legs angle where we see Tuck and Brad looking away, but Sheldon's eyes wide open. Then it switches views to see that Wakeman is in her Skyway Patrol uniform.
Also from Escape from Cluster Prime, when the Cluster starts the second wave of its invasion, Brad watches in horror, and the camera pans down to his legs. Then Tuck drops down from behind him with a "glop" sound effect, to give the impression of Bowel Breaking Bricks.
There's a Lonely Hearts member who, at first glance, appears to be wearing a neck tie. That's no neck tie, or at least not a typical one.
In "Hostile Makeover", Brad explains to Jenny she's going through robo-puberty, and lets her know what it's like for humans. Embarrassed by robo-acne, she puts a bag over her head and complains "it smells like fish tacos!".
During his explanation of puberty, Brad inexplicably shows Jenny a 1950's style showreel of children growing into adults. Little Billy grows up into a handsome man named William, while Little Sally's adult form - a Hot Scientist with an hourglass figure - is dubbed by Brad as "...uh, Big Sally."
In the episode "The Price of Love," which is about Sheldon wanting to make Jenny jealous by paying a girl to be hisfaux-girlfriend, there are a few things. One is that all the popular girls get in on the action, all offering their services for cash. But don't worry, as the original girl put it, there are stripulations, causing Sheldon to go, "Don't you mean stipulations?" Granted, they're "no hugging, no kissing," and a few unreadable things, but some of the connotations with the plot is... interesting for a Y-7 rated show.
If you liked that, you'll love this. In "Voyage to the Planet of the Bikers", the Space Bikers are revealed to have normal day jobs on their home world as staff and faculty in an elementary school. Tammy is a teacher shown standing in front of a blackboard with a diagram reading "birds + bees = babies". While pointing to this diagram she directs her students to turn to page 69 in their textbooks.
Also in "The Price of Love", Brit and Tiff decide to get in on the plan and date unpopular boys for money. After Brit starts flirting with one, Tiff hip-checks her out of the way and says, "Hey! You take the one in the closet, this one's mine!" Brit is later seen leading this boy around tied up, implying that he didn't want to be in the relationship with her.
In "Grid Iron Glory" (where Jenny becomes a quarterback on the school football team) her rival with the episode has the name Jacque and is french. Seems innocent until Jenny calls him "Jacque Strap."