This chapter toed a dangerous line. I get that they're teens and teens are stupid. I get they're fumbling and learning.
But in this one she said "stop" and he didn't. Which is fine cause she actually wanted more, she didn't really mean it. But it's a clear indication that they need a safe word. NOW.
@Elianor Tbf, I din't think this was unsafe? The diamond and turtle back was hardly detailed enough to actually use, I think, and still made a clear point about the collarbone knot.
And the actual bondage was a very simple "prisoner" type (does this have a name?), around arms, above and below breasts. Doubt you can really hurt anyone with that, beyond the actual rope marks.