On page 13 she thinks, "I feel so weak..." and then literally on the same page she's ass-clapping on him so hard her butt cheeks vibrate into a different dimension. Makes sense!
Ah yes, SAVAN always does some great work! So many great tags on display here.
Hmm, it would seem that our protagonist is actually quite perceptive! He noticed that she was getting into the mood, and decided to initiate sex again, while making it seem like it's his fault because he can't wait and promised her a date...What a nice guy.