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Maybe a skit from the "Keye and Peele" show? Or from "In Living Color"?
Rings bells; I'm almost sure a British comedy duo did something like this as a sketch but I can't remember if it was Mitchell & Webb or Armstrong & Miller. I can definitely see a cringingly apologetic David Mitchell being a very English would-be slasher-killer!
Elderly curmudgeon and awkward person. Professional old fart.
@ Ag Prov - That Mitchell and Webb Look did a sketch where Robert Webb as the Politically Incorrect Hero Captain Todger battles David Mitchell as the Politically Correct Villain General Drayfox. Is that what you're thinking of?
@ Mike K. Could you be conflating the above sketch with Mitchell and Webb's 'Identity Killer
' sketch?
CollegeHumor has "Sex Positive Slasher" which the slasher gets derailed after would-be-victim cries out he going to kill cause not a virgin
The more I try to remember this, the more I think I either dreamed it or conflated a couple of skits I saw online. If it is real, I am leaning more towards a self-contained web video skit because I can't imagine it happening in an actual horror movie, maybe not even a Scary Movie type spoof. Anyway, it starts out like a normal slasher movie scene with the killer coming after someone, but the victim points out some way in which the killer's motives/actions seem racist. This keeps happening as he tries to kill other characters, maybe to the point where nobody in the scene dies because the killer is too busy trying to explain he's not racist/sexist/etc. This sounds like a Political Correctness Gone Mad thing, but I remember the humor being more directed at the idea that even a slasher movie villain wouldn't want to seem racist.