How???? You're literally giving the person the video.
no you're not, you're only telling them where it is. the website is the one with the video, they're the only ones who can give it to you. and their responsibility for minors seeing it is lifted with that 18+ warning that's on all research sites. if a minor lies to them, nobody is at fault except the minor, or, arguably, their parents
legally speaking
and the website itself wouldn't care either. views mean ad revenue, and they can't get in trouble for it anyway, so why would they