Shevuot 18A

ואי בעם הארץ ⁠– אידי ואידי ״אכל שני זיתי חלב בהעלם אחד״ הוא!

And if we say that we are dealing with an am ha’aretz, an am ha'aretz, who does not know that it is prohibited for him to have sex with a woman near the expected onset of her menstruation, and who also does not know that it is prohibited for him to immediately withdraw from her if she experiences menstrual bleeding during sex, then for both this and that, his entry and his withdrawal, he should be liable to bring only a single sin-offering, since he had no awareness of his transgression between his two actions. This is like one who ate two olive-bulks of forbidden fat in the course of one lapse of awareness and is therefore liable to bring only one sin-offering. Here too, although he performed two actions for which one could be liable to bring sin-offerings, entry and withdrawal, there was only one lapse of awareness.

ואלא בשאין סמוך לוסתה? ובמאן? אילימא בתלמיד חכם ⁠– ולא חדא לא מיחייב; אכניסה ⁠– אנוס, אפרישה ⁠– מזיד! אי בעם הארץ ⁠– חדא הוא דמיחייב, אפרישה!

Rather, it must be a case where it was not near her expected date of menstruation, and there was no reason for the man to think that the woman would experience menstrual bleeding. And with whom are we dealing? If we say that we are dealing with a Torah scholar, then he should not be liable to bring even one sin-offering, because with regard to his initial entry, he was a victim of circumstances beyond his control, and with regard to his withdrawal, after he knew that she was a menstruating woman, his transgression was intentional, and he would be liable to receive karet. And if we are dealing with an am ha’aretz, he should be liable to bring only one sin-offering, for his immediate withdrawal.