Reality, but unlikely, although this is not something that a reasonable person would take risks if pregnancy is undesirable. Laboratory tests show a small amount of sperm in the lubricant. The big question is how much they are able to get to the egg and fertilize it, but there is an entertaining statistics that the chance of getting pregnant when using a condom is 5%, and that of interrupted intercourse (PAP) is 25%. So, "I'll stick it out in time" is not an option unless you are a fan of roulette.
They say it's a myth, but I haven't checked it. I don't understand all these folk methods of protection at all and the men who use them, let them go to another bed). My health is dear to me in order to experiment on it. And I recommend to all women not to be led by men, but to appreciate and love themselves.