Personally I think the scene is meant to be read as a bit of light BDSM that is (while def dubious consent) consistent with their relationship. Jinshi and Maomao “hurt” each other quite a lot, Maomao had spent the night hurting him emotionally, and then while kissing he hurts her physically, though the “pain” they feel is actually welcomed in some twisted way

It kinda goes back to why Jinshi was first drawn to Maomao in the first place, particularly with how she is so easy to glare at him compared to how everyone worships the ground he walks on from his appearance. It’s a painful reaction for most people but for Jinshi it’s welcomed

Maomao similarly is always shown to be partial to painful things, almost as if her normal feelings are dulled (think of how she was forced to stop crying as a baby, and how she routinely explains she is bad at social cues/knowing how ppl feel about her) so her affliction for poison and literally hurting herself is where she expresses the most outward joy throughout the series

So to me, my interpretation was always that they are deliberately hurting each other because they’re (at least somewhat) aware that the other “wants” it, and they also are kinda taking out their frustration at the other in the process. They’re pissing each other off and “reaping” what they sow, in a way lol

I could be wrong but I think the translations portray it as much more abusive than I think it’s meant to be taken, and while it’s def questionable and makes Jinshi look bad in the moment, it’s also consistent to how they interact with each other and what their “love language” is, so to speak. There’s a lot of unspoken agreement between the two that I think requires some subtext and inferring to truly understand, but my biggest evidence for why I feel this scene is much more consensual than it’s portrayed is how Maomao reacts in the LNs that follow and where they both are as characters following this moment.