Kesubos chapter 3, mishnah 4. This mishnah introduces us to the concept of a mefateh, a seducer - a man who entices a young girl, who does not force himself upon her and does not rape her, but rather persuades and seduces her into being intimate with him.
When we are dealing with a na'arah besulah, a virgin maiden, meaning a young girl who is under her father's authority during those six months following her bas mitzvah, after she has reached maturity - the monetary penalties imposed upon the seducer are paid to the father. The mishnah lists them one by one.
Three payments for a seducer and four for a rapist:
"HaMefateh nosen sheloshah devarim veha'ones arba'ah" - the seducer is obligated in three payments:
"Boshes" - payment for the embarrassment involved, since he shamed her, and potentially her father as well.
"U'fegam" - until now she was a virgin and now she is not, and her value has dropped in real terms: she is no longer the same candidate for marriage that she was, and she will no longer receive the same kesubah.
"U'knas" - a fine of fifty shekel, which is paid to the father.
The rapist pays a fourth, additional payment - "tza'ar" - for the pain caused to her by the force used, unlike the seducer.
"Mah bein ones lemefateh?" - What is the difference between a rapist and a seducer?
The mishnah goes back and spells out the differences between them:
The pain: "Ha'ones nosen es hatza'ar vehamefateh eino nosen es hatza'ar" - the rapist pays for the pain she suffered, whereas the seducer is exempt from this payment, since we assume that there is no pain here.
When the payment is made: "Ha'ones nosen miyad" - he must pay the fine immediately, whether he marries her or not. The seducer, however, does not pay the fifty shekel immediately; rather, this sum serves as her kesubah: if he takes her as his wife after the fact, the sum will be paid in due time as a kesubah.
The obligation to marry: "Ha'ones shoseh be'atzitzo" - he must drink from the cup he poured for himself: if the father and the girl want it, he is forced to marry her and he has no choice in the matter. "Vehamefateh - im ratzah lehotzi yotzi" - the seducer is not obligated to marry her; if he wishes to remain married to her, he may, and if he wishes to divorce her, he divorces her.
It emerges that the seducer faces two possibilities: if he does not want to marry her, he must pay the fifty shekel at that time; and if he did marry her, he does not pay the sum until the moment the marriage ends, and then he pays the fifty shekel as a kesubah.
In summary: in this mishnah we learned that the seducer gives three things - boshes, pegam and knas, and the rapist adds tza'ar to them. There are three differences between the two: the payment for pain, when the fine is paid (the rapist immediately, the seducer when he divorces her), and the obligation to marry - the rapist drinks from his own cup and is forced to marry her if the father and the girl want it, whereas the seducer, if he wishes to divorce her, may divorce her.