Here's one I hate: women need to "save themselves" for the real thing and shouldn't use masturbate until they've had real sex or else they'll be "spoiled." (I've never heard this said about men, but I wouldn't be surprised if they've been included, too.) Even on this very site I've bumped into one or two comments that virgins should stay away from dildos.
Ok, so, "size matters" to some people, to each their own...but assumption that it matters to anyone and everyone, makes someone more of a man, and is always a big factor in the pleasure of vagina-owners...SUPER ANNOYING.
I don't think most people believe that pre-marital sex is sinful. That's less of a widespread myth and more a disappearing attitude.
"Women don't like porn" is annoying (most porn isn't made with women in mind...) but it's part of a greater myth that women don't like sex that much/experience desire, when in reality there are often few ways to express that desire without being degraded for it.
A myth I would like to add is that there is one way to be "good at sex."
That women DO NOT LIKE SEX!!!!! Worst myth out there, wait! NO!!!! That the female orgasm is a myth.
There really should be an "other" category.
Don't listen to anyone that says, size doesn't matter. Size REALLY does matter. Here's a post all about it linkThe Perfect Penis Size]. Vaginal penetration with something the size of a bullet vibe doesn't work. Something the size of the Hoss does matter.
So many myths, so little knowledge. Which ones do you find the most ridiculous?
my most hated myth is the hymen. i mean it exists, yeah, but it doesn't break during sex; it starts breaking down when you start to menstruate. if a woman bleeds when she has sex, it's usually because of vaginal tearing b/c of too little lubrication