Moreover, I heard there were some inconsistencies among the different series. So is it possible to skip (through) one show/season and not be confused when watching the others?

Reading from the sypnosis of all 3 series, 

Together with Me (before they couple) , Bad Romance then Together with Me Next Chapter (they are engaged) 

Fyi, I just finish watched Bad Romance for the sake of watching it before Together with Me series... But there was not much of BL main couple interaction and I couldn't see the chemistry so I think you watch the Together with Me series straight away... BUT this is just my opinion~

ok if i wach together with me and then together with me next chapter is fine ? O_O 

im so confused^^ 

Yes,  if you dont want to watch the bad romance also can... 

 Butterfly:

Yes,  if you dont want to watch the bad romance also can... 

ok i will try with bad romance...but it looks so weird..... like comedy..... xD (not romance or BL) ........ i watched first episode few minutes....xDDDD

It’s so bad, lol I’m watching it for the sake of watching all three movies.  Together with me was sooooooo much better. The problem with this is #1 the subtitles.  I appreciate the “subtitlers“ that take the time to translate  these dramas for us foreigners that can’t understand the language. BUT, first and foremost, you should be able to speak the language you’re making Subtitles in.  I was  SO hoping Lazy Subber had translated this, because she actually explains the cultural references in her translations. Plus  she’s funny as hell.  #2, you have to understand that things that are funny in other countries, might not be funny in yours.  So the comedy bits in this are probably hilarious to Thai people, but to me, as an American, they are goofy, just as I’m sure Days of Our Lives would probably be to a Thai person (although I think it’s pretty goofy too.) #3, this was made in 2016 when the BL genre was still fairly new. I mean this is an OG pre-Tharntype drama! So I mean, it is what it is.  I love the Yiwah character though. She really gets better in the later filmed dramas. It’s too bad this had to be the first one filmed. But like I said, it is what it is. I will watch it until the end because Cho is so damn hot And I hope that he and Yiwah end up together.  I’m sure they will, because this is THAT predictable.