Kamasutra 2.1.15

2.1.15

tatraitat syāt cira-vege nāyake striyo 'nurajyante śīghra-vegasya bhāvam an:āsādyāvasāne 'bhyasūyinyo bhavanti. tat sarvaṃ bhāva-prāpter a:prāpteś ca lakṣaṇam.

This opinion is however objected to on the grounds, that if a male be long-timed, the female loves him the more, but if he be short-timed, she is dissatisfied with him. And this circumstance, some say, would prove that the female emits also.