Reference for Ketubot 145:1

לא תימא טעמיה דרב כיון שכנסה סתם אחולי אחליה לתנאיה אלא טעמא דרב לפי שאין אדם עושה בעילתו בעילת זנות

Do not say that Rav's reason is that because the man has married her without attaching any conditions, he has forgone those conditions. Rather, Rav's reason is that no man treats his intercourse as a mere act of fornication.

Jastrow