Commentary for Kiddushin 44:17
השתא דאמרת הגביהו הוא לרבו קנאו אלא מעתה שפחה כנענית תקנה בביאה כי קאמרינן זה נהנה וזה מצטער הכא זה נהנה וזה נהנה הוא
R'Assi-others state, R'Aha - said: It must walk its full length before him!<span class="x" onmousemove="('comment',' Thus, when an animal comes in answer to a call it is acquired; why not a slave?');"><sup>28</sup></span> - I will tell you: an animal walks by its master's volition; a slave, by his own.<span class="x" onmousemove="('comment',' Even when he obeys a call, he does so by his own desire, unless the master forcibly seizes him.');"><sup>29</sup></span> R'Ashi said: A slave who is a minor is as an animal.<span class="x" onmousemove="('comment',' He has no volition of his own and therefore may be acquired by a summons.');"><sup>30</sup></span>
Daf Shevui to Kiddushin
The Talmud responds that when a slave lifts his master, the master derives pleasure, the slave does not. During intercourse, both parties derive pleasure. Therefore, this does not imply that the female slave is serving the male partner.