In my opinion, yeah under law its the others resposibility to check but at the same time if a 16 year old is mature enough emotionally and physically that they fool other people then you cant really blame the adult. Also the whole age of consent is to protect children and a lot of people forget that so the only reason they want them to go to jail is to punish this "evil". Someone who commits a crime isnt always a bad person. Also in cases where a 20 year old dates an 80 year old or something like that, you should be protecting the old and probably not totally mentally capable and not the 20 year old who is probably using the 80 year old. But of course if i use these arguments irl people just call me a pedo so yeah.