Something probably happened between them based on his reaction after being confronted by some bitch. He may have thought he might put fl in the same or similar situation. Trauma response I bet
It’s basically the thickness of the latex on the condom, so the 001 would be the thinnest and thus uuuh the dude wearing it can feel a lot more, it’s ironic coz the seme is the one carrying the 001
The edging gets edgier in every edge of a chapter