If someone slits your throat in the middle of nowhere, I can
infer you're going to die. And the only way I'd be wrong is if I've fundamentally misunderstood what kills people, or literal divine intervention saved you. If I see a guy holding a knife pass me by shouting "I FUCKING HATE THAT
@beep_repair !", charge into your bedroom, walk out bloodied, and I see you with your throat slit, I can
infer the knife guy slit your throat.
Okay, but inference in fiction is
vastly different from inference in real life. In real life, the amount of available information is typically enormous, and we can continue to investigate until the questions we're trying to answer have been definitively (or at least satisfactorily) answered.
To use your prior example, if you look out the window and see what
looks like rain coming down, you might infer that it's raining. If you still had doubts for whatever reason (if, for instance, you suspected that the neighbor's lawn sprinklers were going crazy again), you could look more closely to see whether or not it was raining across the street. You could look out another window or open a door. You could check the sky for clouds, and so on.
Similarly, if someone's throat appeared to be slit, you could rush over to check the severity of the wound and the rate of blood loss. If the gash were shallow and had missed the carotid artery, the victim might survive.
In fiction, however, our ability to infer is strictly limited by what the author has
decided to tell/show us. In other words, the reader's inferences occur within a contrived and tightly controlled information field. And authors can be very tricky. Authors can plant misleading clues to encourage inferences that
seem utterly convincing to the reader -- but later prove false ("red herrings").
In this case, the author has clearly
implied that the MC gave the man she's visiting a blow job. The panels of chapter 4.5 were obviously designed to communicate that exact implication to the inferring reader. And in my opinion, it's probably true that she
DID give him a blowjob. But we don't know for sure. We only have the reasonable -- but unconfirmed -- inference that the author has encouraged us to make.
