You can especially tell when they make grandiose claims without backing them up.
And they're often victims of their confirmation biases, they've decided that being good-looking automatically makes you drown in pussy.
So they see their good-looking friend bring a girl home after a night out and they're like: "OMG, he can have any girl!"
Talk to good-looking people.
Only recently at my workplace, someone told me:
"Cheating is complicated, because if a guy is tall, good-looking, confident, has everything going for him, and he goes to a party, there is absolutely no guarantee that he'll have sex with a girl."
The guy who told me that? Tall (2m!), good-looking, naturally muscular, low-brow, masculine, tanned, blue eyes, the heartthrob.
Why isn't he banging a girl every time he goes out? Should be easy! Because that ain't happening you delusional incels.
He has more experience than most of us on this forum, and I guess I'll trust his jugement before I trust someone who writes:
"If you're good-looking, 1 out of 2 girls will want to have sex with you!" Nope.