You know, lack of delicacy aside, he raises a surprisingly valid point.
You fap to her cause you "like" her, as in, she's hot.
But once you start LIKING her, that is, considering her interests, her dreams, her feelings...fapping to her just feels wrong, like you're using her. Which is hot in its own right, I guess, but you know what I mean.
Also, gotta love the comments saying "so the MC faps to the FMC huh? Nice". Like we didn't know that already. Even ignoring all the boners she's given him, in Chapter 3 or something he literally goes to the toilet after she touches him, can't remember the details.