Kamasutra 2.1.27

2.1.27

tatraitat syād upāyavailakṣaṇyavad eva hi kāryavailakṣaṇyam api kasmān na syād iti/ tac ca na/ hetumad upāyavailakṣaṇyam/ tatra kartrādhārayor bhinnalakṣaṇatvād ahetumat kāryavailakṣaṇyam anyāyyaṃ syāt/ ākṛter abhedād iti/

It may be said that if the ways of working in men and women are different, why should not there be a difference, even in the pleasure they feel, and which is the result of those ways.

But this objection is groundless, for the person acting and the person acted upon being of different kinds, there is a reason for the difference in their ways of working; but there is no reason for any difference in the pleasure they feel, because they both naturally derive pleasure from the act they perform.