Okay this is going to sound insensitive, but Nadech doesn't know where those nang'eks' lips been at. At least with Yaya, he knows for the past 8 years. ( sorry, this is just me joking so don't take me seriously).
Anyway regarding going all in, those other lakorns - how do we know it's Nadech that's not going all in. I don't follow past lakorns of Taew or Mew or ( who's else he's with? that's it
), but have they been known until recently with Mark/James Ji's lakorns that I've watched, to do real kisses? Maybe it's the nang'eks that also request for that.
As for MLFTS - I heard there's a lot of kissing so I'll reserve my judgement until I see the lakorn to see if he's truely not kissing anyone besides Yaya.