While everyone has different levels that they find acceptable, it feels to me that Zenimax is pretty good at at getting the tone of their innuendo and risque elements exactly right; sometimes flirty or smirking innuendo, even rising to an occasional raunchy line, but forever falling (frustratingly!) short of outright lewdness.
There are all the emotes, like "kiss this", "flip the bird" (a literal bird!). There's one (or it might be a memento? I forget) where you offer to sell a potion to enlarge someone's rooster: some lovely innuendo right there!
There are all the Treasures (so many of these books, I'm sure we'd all love to have be readable items, instead of descriptions!). Here's just a sample:
Art Book, "Allure of the Sweetroll": Rare art book, 'Ong's Passion: Allure of the Sweetroll,' depicting healthy unclad Imperials holding artfully placed sweetrolls.
Cyrodilic Boudoir Etching: A partially torn but otherwise well-preserved etching of a bawdy scene, most likely brought to Murkmire by a lonely Legionnaire.
Dibella Napkin Holders: Each of these fashionable napkin holders was molded into a voluptuous depiction of the goddess of beauty.
Dibella's Bosom Night Favor: A bust of the god of beauty and erotic instruction, kept in Nord bedchambers to make nightly activities more … invigorating.
Ebony Mermaid Figurine: This tiny stone mermaid curls her tail seductively. A common fertility idol for High Isle commoners.
Edifying Illusio-Scope: Bulging device with inward-facing goggles and a crank that, when turned, shows the viewer moving images of Bosmer procreation.
Embossed Leather Picturebook: The Conquests of Vivec' depicted on supple leather pages inviting to the touch, the proportions appear highly exaggerated.
Erotic Argonian Etchings: A set of limited-edition etchings of Argonian erotica. It is impossible to discern the gender of the participants.
Erotic Found Object Mosaic: Assorted junk and scrap arranged to resemble provocative figures in repose, strategically oiled to give a glistening sheen.
Erotic Green Pact Drawings: A collection of plant life drawings that are strangely suggestive.
Feast of Souls Miniature Painting: Vampires of all races encircle a group of willing blood-friends, some already offering necks or naked limbs.
Glenmoril Wyrd Leg Cologne: The sisters of the Glenmoril Wyrd mix a pungent concoction of herbs and apply it to their legs for the pleasure of their wolves.
Guide to Approved Methods of Procreation: Illustrated folio from the Thalmor depicting methods of coition "that properly reflect our Altmeri heritage."
"Lusty Argonian Maid" Art Folio: A well-worn book of stimulating images illustrating the popular tale of "The Lusty Argonian Maid."
Mother Morrowind Fertility Fetish: Iridescent green-gold glassite statuette of a beatific Almalexia, arms crossed over her pregnant belly.
Pamphlet of Erotic Engravings: Khajiiti pamphlet showing various forms of erotic dalliance, illustrated by stylized drawings of astoundingly lithe cat-people.
Risque Boudoir Portrait: A portrait of a buxom young Nord wearing nothing but a horned helmet and a provocative smile.
Risque Etching: This revealing etching of a masked courtesan was deemed too provocative to display in mixed company.
Tickle Tail Toy: When looped around the tail, this band of downy feathers becomes a fearsome tormentor. Popular among bullies and courting pairs.
Yorran's Yarns of Cyrodiil, Illustrated Edition: Amusing and often bawdy anecdotes detailing a Nord's adventures in the Imperial City, complete with explicit illustrations.
And then there're all the flirty characters and lines of dialog filled with innuendo!
What's your favorite bit of lighthearted naughtiness from ESO?
I think mine's the "Mistletoe Posterior" emote