I'm not a teen (far from it), but I'm with the kids on this one. The vast majority of sex scenes in movies are awful. They're awkward and totally unrealistic. It completely takes you out of the movie. Most sex scenes are not engrossing or engaging, they don't immerse you in the story, they push you out of it.
Most every sex scene feels like it was made by someone who's never had sex. Every angle is the right angle, every thrust is ecstasy, it's nonsense. It's like someone who thinks the covers of romance novels are depictions of real life.
There are a lot of intimate moments that can be portrayed convincingly enough on film, but sex is rarely one of them. And it's just not necessary. Let the audience infer, let us use our imaginations.