I strongly agree with @Sim Yeon.

I just like to add that the end wasn't perfect, but it was good enough. Time travel/body swaps stories will never have a completely satsfying and logical ending. 

I felt the drama has given us a good enough ending. JBH got back to present and his own body. I completely reject that he would have prefered staying as queen, and just to make it clear. I am fully behind the rights of LGBTQ+, and have no issues whatsover with gay love. Some of my all time favourite books and movies are about gay love.

But, I just don't believe that the King would have loved JBH if he was looking at a man. 

So, at the end JBH got what he wanted, but he is now a kinder person because of the queen The King and Queen seemed happy despite the King missing some of that old spark of JBH. The Queen is now more assertive and confident because of JBH influence.

But, again, all that doesn't really matter that much to me. This series is a comedy gold. And SHS performance is one of the best of its kind  I have ever seen in  any language, and I am almost 50.

For me it is certainly happy ending tinged with a bit of wisfulness, but I don't see how we could have a better one.

For all those who want BongHwan to remain in the Queens body, I like to ask you a sincere question.

Would you be willing to go back few hundred years in the wrong body and you have to have sex with someone you like, but of the opposite gender you are attracted to??

BongHwan liked the king, didn't love the king in a romantic way. that was So Young.

I think he is incomparably better off with that end rather than being stuck in a woman body.

Bonghwan suffering from the first part of the series is played for laugh, but if it was taken seriously, then his suffering is massive.

We now support (at least in some part of the world) transgender people because we acknowledge their suffering of being stuck in the wrong body, so imagine adding the time period. How can you say that Bonghwan is better off being stuck in the queens body???

People can get over heartbreaks. He will be fine in modern day.

Sad ending for me

Firstly,yes it was good that modern person returned to his own world but he lost everyone he loved in a minute,that was too cruel,some might say he loved the king platonically,it doesn't matter,he loved him in his own ways and he lost him,he loved the kid and couldn't even meet that kid,this one particular thing broke my heart and he also lost some wonderful friends,it looks like he lived a very empty life in the modern world,I feel pity for him and I hope he can move on leaving all this as a good memory which I doubt,SO ON HIS PART HE HAD A BITTERSWEET ENDING.

now for the queen part,she definitely had a happy ending but it's just a temporary one,the king will soon not be like the way she wants,if she can achieve the King's love than that's good,(wouldn't work with me,as I don't like my leads moving on that easily)but I don't think that will be possible,THE KING NEVER LOVED THE QUEEN.

Now the king,this poor guy,damn I cried my hearts out when he said he missed something and was so happy when he saw the queen,oh you poor guy,the creators did him dirty,just imagine you think finally you can live happily with your loved one but it's not the same person,he fall in love with the modern person's tactics, behaviour, personality.And if they meet as man,I think this wouldn't be possible as both won't accept it and both being straight doesn't help,but it doesn't change the fact that the king loves that guy,and now if he meets him as a man I think he will be in a lot of mental trouble but he will still at the end love the guy.Now if he can move on from him than that will be great but that is unlikely and I don't think he will come to love the queen as both are completely different from each other,so now forever he will live in confusion and heartbroken.Poor guy,

I cried my eyes out at the That's why it's a sad ending for me.