So, do you think these scenes are needed? Especially in so much detail of the moments?
I think it all depends on the age group the book is for. For example, I think absolutely NO love scenes should be in a book dedicated to kids 15 and younger. A book can be an excellent read without love scenes, even if it's a romance book, and for kids and young teens, they shouldn't really be exposed to these love scenes until they're old enough to deal with it. Especially in today's society where teen pregnancies are becoming a common thing, sexual content in books should be strictly regulated.
Should the parents keep a closer eye on what their kid is reading? Should younger kids (before teens or even early teens) read about all these scenes? Can they really handle the situation?
Definitely parents should keep a close eye on what their kids are reading, because books influence childrens' minds more than we think so. And definitely, younger kids before teens and early teens should NEVER be allowed to read sexual content until they're past the age of 16 at least.
Should younger kids be only allowed to read 'Kid's books' so they don't read about the stuff that's not meant for them? But then some kids like to read stuff beyond butterflies and gardens, what should be done for that?
I know of lots of kids books that are not about "butterflies" and "gardens" and that don't have one bit of sexual content. I think "kid's books" is a bit broad, because lots of good books are deemed "children genre" and have a really meaningful content. For example, take Harry Potter for instance. It's actually aimed for kids, but there's lots of intricate detail in it that draws kids (and other age groups) in and at the same time has no sexual content at all. I don't think sexual content is needed to make a good book actually. I've read so many good books where the authors were not comfortable with adding sexual content, and they're really good, so if kids want to read something meaningful, there are lots of good books out there for them with no sexual content, so why not try those?