In A Very Merry Chipmunk, Alvin decides to give up the harmonica for the saxophone, and receives pointers from Kenny G. Alvin then asks him "Now, do I suck or blow?" Simon responds with "You definitely suck."
In Club Chipmunk: The Dance Mixes, Alvin covers "I'm Too Sexy". That alone should be enough, but there's even a line with him moaning about how he loveshis Calvins.
In general there seem to be a lot of Panty Shots (from the Chipettes and other young girls) for no reason, although that may be an attempt at realism, as some of their skirts are quite short.
In "Romancing Miss Stone", during the scene where Alvin and Dave are duelling over the hand of Alvin's teacher, Alvin yells out "Take that, you gigolo!" as he hurls a water balloon at Dave.
In the episode "Sploosh", Brittany's character at one point asks Jeanette (as the mermaid), "Are mermen sexier than human men?"
Even better from "Simon Seville, Superstar", Simon (an eight-year-old boy chipmunk) is asked how he feels about being a SEX SYMBOL! He is unsure how to answer that directly, but suggests that his glasses may have sex appeal.
In "Cinderella? Cinderella!", where Brittany dreams herself in the role of Cinderella, a scene of her forced to do various chores has her giving baths to her sisters. Both Jeanette and Eleanor's expies in the dream are shown sitting in small bathtubs, uncovered from the waist up, with small dots drawn on. Admittedly, such a thing back in the 80s was probably no big deal unlike today, but come on, what the hell?
Also, depending on what The Chipettes are wearing, it seems like the animators like to draw them with busts from time to time, despite them being eight-years-old. Most notably, in the episode "Staying Afloat", bikini-clad Brittany constantly goes back and forth between being flat-chested, and having breasts.
In a storybook adaptation of the episode, "The Greatest Show-Offs on Earth," an entire page has The Chipettes doing their acrobatic number, drawn with both breasts andHartman Hips... and again, did we mention they're only eight years old?
"Dreamlighting", which parodied the show Moonlighting, has what appears to be a distraught Alvin suffering a hangover. Then we see that he's just been drinking root beer and he's had far too much.
Alvin sees a psychiatrist in the episode "Alvin and the Analyst", who supposedly is a caricature/parody of a real-life sex therapist; granted, Alvin wasn't seeing the shrink for those kinds of problems, but still parodying a sex therapist on a kids' show?
The entire "Proud Mary" number from the episode "Goin' Down to Dixie" so much that it actually spawned an entire article based on a troll's YouTube comment that The Chipettes are, "A pedophilic rape waiting to happen", on the grounds that their New Orleans-inspired dresses were inappropriate for girls their age, while others argued that not only did the dresses fit the number they were performing, but they're chipmunks, not little human girls. In short, The Chipettes' performance of "Proud Mary" is almost as controversial today as their "Gettin' Lucky" number from The Chipmunk Adventure had become.
Since they're wearing 19th-century showgirl dresses and stockings, the girls are VERY covered up, much more so than modern pop standards. Their foster mother is also sitting in the front row and clapping along. This one's gotten blown way out of proportion, to say the least.
In the "Bigger" episode of Chipmunks Go To The Movies, Alvin and company wear shirts with their band name on it. "FUR BALLS". (Even when Alvin's much older.) It's almost enough for a Spit Take if you're watching as an adult.
The scene where Brittany and Jeanette have to get past a swarm of snakes. How do they do that? By charming them, of course. How do they charm them? By singing. (While wearing Bedlah Babe outfits, too) And the name of the song they sing? "Getting Lucky". No more need be said.
And the snakes go rigid when they're actually charmed. Maybe a blatant Visual Innuendo but, to be fair, that is actually the normal position for cobras who are either preparing to attack or are being charmed.
The fiesta the boys take part in in Mexico City might actually be worse than the now-semi-infamous "Getting Lucky", and a case of Double Standard — the human women they dance with are wearing very low-cut blouses, the Carmen Miranda number they perform has Alvin getting full-on smooched after asking a little girl whether she likes his hips, and "Cuanto le gusta" is Spanish for "she really likes it!"
While The Chipmunks and Chipettes struggle with controlling their balloons, Klaus can be heard muttering, "Gott in himmel!", which is German for, "God in Heaven!", which can be interpreted as a swear against God, which is usually unheard of in children's entertainment.
Alvin: It's Aunt Jackie. She's making us a zesty five-course meal. Dave: Really? Well, can I talk to her? Theodore: She's practicing her pole dancing. (Alvin and Simon look at each other) Dave:Pole dancing?
Learning/practicing pole dancing has recently become a well known workout, however, so it might have been just that. (Aunt Jackie was also in a wheelchair, which might explain Dave's surprise.) It did, however, originate from strippers, so it still counts.
For that matter, in the first movie, Simon mentions the very-short-skirted and attractive housekeeper "Uncle Ian" sent over is also a masseuse.
In Chipwrecked Alvin swings right into a tree moaning "Ow! My acorns!"
Also in Chipwrecked, from Ian, who mentions that "one time Snoop started a blaze just using two carrot sticks!"
In Road Chip, Miles tells the Chipmunks that Dave will leave them in the forest holding their nuts.