I think the opposite lol in the way that for me, when Nadech is on stage or in a lakorn, he makes me believe that he really loves this woman, whoever she will be but I agree with you that at the first second when he returns to the real life or off camera, he becomes Nadech again, he is looking for Yaya. As for Yaya, she's more pro in hidding her feeling in front of the medias that's why, Yaya in an interview alone or Yaya in an interview with Nadech is two different persons. When she's with Na, she's natural, super sweet and cute. What I know about her too is to make a "urassaya's since 2011" shirt to Na, she must be as deeply in love as Nadech and jealous
Her message is
"you're mine since 2011" haha. Each time Nadech revealed sthg private about them like the shirt or the scarf , it's like Yaya doesn't know how to behave and is super shy.