TheStarsOfTheLion

Because 15 is age of consent in Thai. A 15-year-old there can already give consent for having steamy threesome with adults without needing input from their family, let alone just hand-holding and mouth-kissing.

The moral is that Thai people consider 16 year-olds are matured enough to decide about sex on their own. Your country might say it need to be 18. But some other countries might say it need to be 21, and in those, your idea of a 19 and a 27 is still considered unlawful, perverted. While in Thai, it's lawful.
This is a Thai production created by Thai people on Thailand to broadcast in Thailand, they only need to follow Thai laws. If it isn't suitable for your country's laws, don't watch it; but don't force your country's laws and ethic on others and call they names. Dismissing others' ethic and only considering yours valid is an act of racism.
Furthermore, the images and characters portrayed in the series are of two high school students, not a 27 and a 16. Ship the characters, not the actors. You don't call out "cheating" and "unfaithful" on married actors for taking on the roles of husbands of other actresses on the scenes. It's the same here.

If the law says that a 15 year-old can lawfully have sex with an adult, what is your claim to say that a 16 year-old kissing the mouth of an adult is wrong?

It's sexual activity the thing they base on to decide whether it's sexual harassment or someone is a pedo or not. You are contradicting yourself.

And you are racist for saying that your way of living is valid while Thai way of living is disgusting. Thai people abide by Thai laws, not yours.

Age of consent in Thai is 15 so even if it's a 16 year-old girl, it would be no problem. If being 15 year-old is legal to have sex, then those scene are not 18+, but 15+ in the country it was produced.
The American way of the age of consent of 18 is not the only way of living in the world.

No. It doesn't require "full-on real unsimulated sexual intercourse".
Actions such as kissing on the mouth, licking the face, touching the body in intimate ways are considered sexual, and doing so with non-consensual persons or persons under age of consent - which are deemed as cannot give consent, thus non-consensual - are considered sexual harassment.
Ages of consent are varied between countries, but as I recall, non are below 14. So if you touch the body of a 12 year-old in a sexual way (gliding across their body, perhaps), no need for full-on sex, you can still be charged with sexual advances on minor.

If it's not illegal in your country, then you shouldn't be concerned. Choose by your own interest.
Don't let other people override your country's laws and ethic with their own and dictate how you live.
Also, the characters depicted here are two high school students, not a grown up and a 16 year-old. Do you consider it's cheating when a married actor takes the role of a husband of another actress on the scene? Here is the same.

The age of consent in Thai is 15. Thai people need to abide by their laws, not yours nor mine. The complains about ages are either baseless, or an racist attempt to dismissing Thai ethic.

I agree.
Also, update: According to a commenter here and my own research, the age of consent in Thai - the country in which this series was produced - is 15. That means even if they do real-life fan-service, we have no right to critique. Thai people in their own country abide by Thai laws and ethic, not ours; to say otherwise is borderline racism.

It's those people who are the creepy ones. They watch the series depicting the relationship between two characters, but they don't think of the characters but the actors - the real-life persons - who may have their own lovers, their own families in real life already and yet those people still want to force some relationships on them. Some even acts up and be rude to the actors' real life lovers.
Delusional.
It should be the characters depicted on scenes that we should focus on. Else, two twenties-year-old actors takes on the role of a twenty and a sixteen in a relationship would be okay? Or an adult actress takes on the roles of a centuries-old vampire stuck in the body of a teenager hooking up with an old man would be okay? No, they aren't. Despite the actors/actresses being of age of legal, what portrayed on scenes is what really matters.
Here in this series, it's about two high school students. There should be no problem with that, as long as they don't do off-scene fan-service. And don't ship the actors (I can't emphasize this enough).

This is mydramalist. Don't be concerned too much on rating here. It's unreliable. I have seen someone complained about acting and camera works, then dropped this series after 1 episode, but rated series with cringy and blank plots such as 2Moons and Cutie Pie with 10/10.

That mother of Nut is a nightmare. She is his mother, MOTHER, but she didn't act like one and be his emotional support. She acted like a spoiled child, wanting to live with her dead husband rather than her living son, causing her son so much stress. And she intentionally made that decision while being on med and sane, yet had the nerve to play the victim card and ask why her son was mad.

No. What make you thinking of that?

I would like to see when facing the possibility of being homeless, penniless, jobless, would you still be on your high horse or would you be a "coward" like Ben. And Nueng isn't really brave in that situation. He is rich and privileged, so he has no fear admitting being homo. But Ben would put his life on the line doing that. Some parents can really disown their child for being gay (or at least that thought was instilled on the child due to parent's behaviour).

With a father like that of Ben's, coming out can have the result of being disowned and kicked out of the house. A high schooler like Ben, no money, no job, no house. Think about it. So he can come out to some trusted friend, but not his father, because he would gamble on his life doing that.

Nueng, on the other hand, is the only child of a wealthy family, and the sole inheritor with supportive and protective mother (father was out of the picture). Being gay would not sway him from that position, he would have no trouble at all to come out, so he has no need to stay in closet.

I would say that if the photo was not revealed so that both of them have the chance to foster their feeling in private until Ben can graduates and makes his end meet, the out come can be vastly different.

Regarding point 4:
Are you really certain that most Thai people are already open-minded about LGBTQ+, and there is no need to tackle homophobia issue anymore?
Last I check, gay-marriage is still not approved in Thai.
Here in my country, people seem to be open-minded about LGBTQ+ too, but that is on social media only. Behind the back or in private, it's another matter. The very people that changed their social media's avatar to 6-colored rainbow following the trend, used homophobic slurs. People can say that they have no problem with gay whatsoever but also say they wouldn't be friended them and would stay away from them. There are whispers behind the back, comments on forums, and the words parents said to gay characters on TV...
I afraid the situation in Thai is the same, and you were over-optimistic there.

If Prang was truly sincere, Preuk would have already withrew from the relationship. However, she was a two-faced, acting innocent in the front but snidely mocking Preuk behind the back; then instead of confronting her boyfriend of his cheating behavior and demanding him to end it (like a normal victim would do), she helped him to trick and frame the people her boyfriend lied to.

Prang condoned her boyfriend's cheating behavior, even helping him sleep-then-bait by setting up and shaming his male partners, so sure of herself that all of those was just a fling and he would come back to her in the end. Her boyfriend kept cheating and even slept with the guy she hired to trap and frame Pruek.
Sin kept sleeping around, using Prang as a front to mask his conquest among gay guys, ended up with his parents finding out about his unfaithful and playboy lifestyle.
Preuk managed to come out to his mother and moved on from the a-hole.

You can watch this series on the internet too, you tube channel one31 has all 17 eps with Eng sub (and being official videos).

My own opinion on this series is that it's good, being better than LOTS of other Asian BL series.
While it isn't focus much on romantic moments (the things BL fans call chemistry and shipping contents), it presents the struggles, the ridiculous double-standard on LGBTQ+ (you can be a hard-working, kind, honest, trust-worthy brother/son but if you are gay then you're still worthless; while a cruel heartless back-stabber is regarded highly than you just because he chases after chicks), and deliver the right message that a gay guy like me want to tell the world: treat me with respect deserving for a fellow human, no need for less, no need for more (unlike the "talk" from some ally posts that depicts gay guys as women's best friends with fashionable sense and good values and such; all misguided, I say; gay guys are just the same as any other guys). The series has a good understanding regarding LGBTQ+, gay in particular, and aims to present it to a wider, more general audience base than typical BL series (which aim for BL fans, who often looking for skinship and even fetishize gays sometimes). I appreciate that. The acting of the main characters, and good pacing of the plot really help too. I was engaged.
I understand that each person has their own taste, and TV dramas, lakorn in particular, may not be the cup of tea for some. I respect that. It's just that I really like this series, and I'm looking for some fellowship. Hehe. So I recommend to you this series :))
(This is my last attempt. Promise!)