The issue is that it needs to be informed consent, rather than just “they said yes”… or even worse, “they didn’t say no”. I feel like I need a shower just typing that.

In this instance, the girl may have seemed like a willing participant - but anyone “consenting” when they’re below 16 (or whatever your local jurisdiction’s legal age is) needs to be taken with a truckful of salt, and in most cases is entirely inadmissable as a legal defence. I’m all for granting young adults the opportunity to make most decisions for themselves - but there are certain grey areas that their age renders them vulnerable to coercion or exploitation, sexual interactions being one of them.

There are of course very narrow exceptions - most notably the Romeo and Juliet laws, but it’s generally accepted that if one party is below the age of consent while the other isn’t, then the consent is not informed and therefore not valid.

It doesn’t have to be age-based either. It can be in environments where there is a sufficient difference in power dynamic (big difference in levels of seniority in the workplace; persons with learning disabilities or additional needs; or those with dependency issues) where consent is not informed and is the subject of coercion rather than genuine consent.