or what world you're living in because in my world i have to carry ID to buy a bottle of wine
Same world as you, but fortuntely/unfortunately I am somewhat older so don't have to prove I'm over 18 in the way you've been needing. Sainsbury's seems overly strict if they are asking for ID just for walking down an aisle. I assume they'd have a mini heart-attack if a mum walked down that aisle with a toddler either walking or on the seat of a trolley. Something to complain to the management at Sainsbury's about - a 'jobs-worth' going over zealous on checking IDs in my view.
"dont understand what you mean by already been shown?"
Merely to comment on material broadcast in recent months/ years. Such as 'Is oral sex safe' on BBC Three (recent) or various shows on C4, C5, which could be described as "explicit" in terms of language or visual content.
As for recording, what I was getting at was the possibility in some households for a digital box to be in a teenager's bedroom. With some teens being far more clued up than their parents (such as being able to pause a live broadcast if you have various Sky or other boxes), it is far from impossible that even if one of the 'house rules' is "in bed, lights out by 10:30pm" so a teenager could not watch something on BBC Three, C4 or C5 at 11pm. it's not that impossible to understand a teenager recording a show which is on late, and watching it atanother time.
So while 'dedicated' adult channels are not going to be freely viewable, with PINs to prevent viewing for example, the 'problem' is still out there, because how many parents would 'PIN-protect' a BBC channel, C4 or C5 (if it is even possible). (I don't have a Sky box and have not used one for maybe 10 years, though PIN-locking was available back then too.)
That's where a parent discussing material that is or is not acceptable seems more important to me than trying technological solutions to limit/ censor what is viewed, when so many non-adult channels can include scenes of violence, bad language, and yes, sexual material too, I see there being a responsibility for parents to do more, not less.