Alison: You know Illustrator, right? Ivy: Oh, totally! I really do know that one. I wasn't lying to pad this resume or anything, 'cuz if I was lying, I would have to say I don't know Illustrator at all, and it's weird and scary to me!... Because that's not the case.
T-Rex: I'm CERTAINLY not writing erotica in my head right now. T-Red:(thoughts) Aw man! Why would I even say that??
DOUBLE K does this with Simon attempting to pose as a prostitute.
Simon: Just so we're clear, you want to pay for sexual favors, right? Not that I'm trying to establish probable cause or anything!
In Dragon Mango, Bleu Berry and her father Goz (a dragon) get into a heated row. When she counters his threat to tear her to little pieces and feast upon her entrails by pointing out that if he does, he might never have an heir, he threatens to eat one of her friends instead. In response, she makes a presentation to her class on how to defend against dragon attacks entitled, "Discussion Intended to Educate Defence Against Dragons" (DIEDAD), which includes a diagram of an "entirely hypothetical dragon" labelled, "Generic Dragon - Not Particularly Based on Anyone's Dad".
Don't even start with Tedd's father who is very bad at covering things up, but still somehow makes it work. It includes a lot of things like:Ecology of Anteaters (Not a Spellbook) and other such cover-ups.
One of the more ridiculous being putting aliens in shirts that say things like "human" or "not an alien". And it works. Probably mostly because of the Rule of Funny.
Constantly by Dan himself in the commentary. "Anyway, that's all I have to say about this comic. There's absolutely nothing else to comment on. At all. Nope! See you next comic."
"And then there's the 'Party' form, who probably isn't a lesbian but acts like it to put on a show for the men, all the while giving the women she makes out with false hope before leaving with some guy!...But that, uh, that's just a theory and not at all based on anything from my first year of college...
ThisExterminatus Now strip makes fun of this trope, with a spy camera clearly marked with a "Property of Mobian Inquisition" label, with a suggestion by Jamilla that the label should have read "Not property of the Mobian Inquisition". Morth sarcastically snarks that that would have fooled him completely.
Full Frontal Nerdity: During a Dungeons & Dragons game, Frank describes a monster that runs down the hall, at which point Lewis and Nelson begin discussing whether they should chase it or not when suddenly there's the sound of pages flipping from Shawn's speakers (Shawn is a webcam). Frank asks if he's looking up the monster, but Shawn claims that he's merely checking out his company's health insurance policy, then announces that his policy is "so good, it would cover me if I was attacked by a reptile that spits acid and has razor-sharp claws with reach attacks."
In General Protection Fault, Nick gives these regarding his job offer from JCN even before he's given a situation where he should be denying anything (such as when he overhears Ki and Sharon talking about what Ki will do for a job). Ki presses him, making a few guesses about what has got him nervous, until she finally gets it right.
Nick: Nope! No job anxiety here! Didn't get an impossible-to-turn-down dream job! Nosiree! Not me!
Girl Genius does this with the "Revenge of the Weasel Queen" story. A Spark who is obviously said Weasel Queen begins to describe what's going on in a neutral way, but quickly demonstrates bias and sparksanity.
Nobody in Saves-a-Fox's party in Goblins even knew it was possible for monsters to level as adventurers before that character denied having done so.
JADE: he was just here wasnt he DAVE: no JADE: how do you even know who im talking about?? DAVE: look all i know is egbert most definitely didnt just appear out of nowhere and catch me weeplaughing at my selfies
In Keychain of Creation#251, Marena's patient attempt to explain to Secret how she and Racer are not members of a nonexistent secret society that does not in fact wear white veils to identify their members and has no political influence whatsoever.
Son: Dad, have you seen mom around lately? Father: I don't appreciate you accusing me of killing your mother.
In Narbonic, when Artie asks Helen if the experiment she's part of had a control group, she says:
"You mean other clones... adopted out to ordinary families, living normal lives until madness sets in? Some half-dozen identical blonde women, eventually hunted down and assassinated by my mother for dissection, as I would be if I hadn't bought a rifle? Why, Artie! That would be deeply unethical!"
Tentacle Boy from NSFW Comix denies contemplating lustful thoughts.
Qwerty (with a guilty expression): It's not because a middle school science fair project accidentally created a time/space vortex which sucked up the sacred Crimson Sea (and adjacent religious study center and theme park) transporting it all to a gas giant in a distant solar system in a temporal causality loop! (beat) Yeah, that's not why it's there.
Also in "On the Origin of PCs", when Roy offers Elan the last spot on the team, Elan in his excitement promises "to be the bestest bard ever... and never accidentally lead you into an ambush..." Roy notes at the time that "That's an oddly specific promise..."
This one is a little more vague, but still a great example.
In this one, Hannelore has just given first aid to Marten, and Faye jokes that she wanted the opportunity to collect Marten's blood for cloning. It was a joke, but she jumps and exclaims, shocked:
Hanners: What?! I would never do that!
She goes on to explain why exactly it would be scientifically impractical, and that at most she could analyze Marten's genetic history. The room is very silent after this. (And they don't even know that she has just collected a sample of his blood).
They use the trope again in this strip. Again in relation to Carlyle.
The tagline for the secondvolume of Roomies! is "It's totally still about college, we swear!" The cover is a riff on Giant-Sized X-Men, with the collge cast as the original X-Men, and SEMME as the All-New All-Different team.
Torg: Don't be silly! Besides, the bathroom doesn't have any windows... or employee entrances, or air-ducts, or crawl-spaces. No forms of escape whatsoever.
And the Guacans of the Punyverse: "We have one of the most expensive, broad reaching tourism departments in the universe! You can't walk a block without seeing a 'Come to Chau-5, we won't eat you' billboard!"
In VG Cats, the chemist from The Legend of Zelda: The Wind Waker who didn't look in Leo/Link's bag and didn't see any faerie in any bottle. Leo/Link takes it as face value, so he just strongly advises him not to blab.
In Zebra Girl Sandra lives and breathes this trope along with Bad Liar as she tries to rationalize her new demonic appearance. It's easy to see why Mike wasn't fooled.
Sandra: I'M NOT A DEMON!!!
In Myth Tickle, when Thunder Bell asked Boody where Thor was, he said, "No matter [[[where]]] he went, he is [[[not]]] behind that tree." Imagine Boody's surprise that that was the first place she looked.
Doc: Hey Roj? Did you take my last Dew? Roger: You can't prove anything! I don't even own a flamethrower. Doc: Oooh-kay. I was just asking because... Roger: It must've been Swampy! He probably took it! Doc: Well, Swamps doesn't usually set fire to the fridge to cover his tracks.