Mmmmmmmmm this is a good question that I frankly think depends on when you think Ronan develops feelings for Adam. I personally think pynch is so awesome because their relationship develops over time rather than romance right off the bat. I’M GONNA GO HARD PREPARE YOURSELF.

Ronan was initially, and I believe canonically, extremely jealous of Adam and Gansey’s relationship. Adam himself states in TRB that his relationship with Ronan is rocky and they rarely have an interaction alone. Ronan strikes me as being someone who is very much averse to change, so anytime something in his life is shaken up he’s going to be wary of it (i.e. his reaction to Blue).

I think most likely Ronan starts to develop feelings for Adam VERY late in TRB/early TDT. Now, developing is completely different from actually acknowledging. (I’m purposefully leaving out the Ronan beating up Robert Parrish scene because I don’t think that it is in anyway romantic and I think it would honestly be a misinterpretation of the scene to look at it as something Ronan did to express feelings for Adam. He did it because Adam is his friend and he hates seeing people hurt, especially when they can’t defend themselves. There was no romantic inclination there.)

In TDT, we see Ronan struggling with his sexuality (there are far more eloquent posts about Ronan’s reaction to his Kavinsky/Adam dreams and what they mean so I won’t try and explain them), I think he most definitely has feelings for Adam, however whether he fully recognizes/accepts them is questionable. 

He pays for Adam’s rent, and we see him get jealous and possibly even hurt when Adam jumps to conclusions and assumes that it’s Gansey who paid and not him. However, Ronan doesn’t really fully recognize why he’s jealous  and brushes it off. So this kind of gives in to  the idea that Ronan didn’t do this to be romantic, rather, “I like Adam, I want him to be okay, I will do this for him because he is my friend.”  He get’s jealous/sad because Adam doesn’t automatically assume he would be willing or the one to do something like this. And yeah maybe he does it because he likes Adam but it’s not a romantic gesture.

This brings me to, THE MANIBUS. Ah, the manibus. I think here we have the first start of something semi-romantic. It’s the most Ronan thing in the world to think so much about how Adam’s hands must be killing him, dream up a lotion for him, and then basically just chuck it in his car where he will find it but Ronan himself won’t actually have to be there. 

This just screams 3rd grader with a crush to me. It’s so “run up to them in the school yard and throw a flower at them and run away”. To me this is the first start of acknowledgment on Ronan’s part, but it’s up to your interpretation whether or not you think it’s romantic. For me, it is. I can see the beginnings of Ronan reaching out tentatively here.

Reasoning: there are a myriad of problems he could be fixing with his dream powers (something to help Gansey sleep, something to help them see where Maura is, and so on), but he chooses to dream up a special lotion for Adam. It’s different than the rent I think because at the end of TDT we see that he has somewhat come to terms with his sexuality a bit and I think that he has finally begun to acknowledge his romantic feelings for Adam (see “second secret”). So by BLLB, he’s accepted those feelings and this is him acting on them.