I really wanted to like this drama and went in with positive expectations after reading the praises of it. Too bad it did not really capture me and left me rather disappointed in the end. Let me explain why. (On a side note, this review is based on my feelings and enjoyment I felt while I watched the drama.)

The beginning was promising and I liked the first two episodes but that changed when the story progressed and things between Teh and Oh Aew got (even more) complicated.
I tried hard to understand the characters, their motives, feelings and actions. I can imagine how confusing it must be for Teh to being sure he's straight but getting confronted with growing feelings towards his friend Oh Aew, but for me that does not justify his actions especially when he saw how much he hurt Oh Aew with them.
As for Oh Aew I wondered why he stayed close to Teh when he got repeatedly hurt because Teh was unable to be true to himself and others and actually speak out about that. When you care for someone no matter if it's out of love or friendship or any other reason wouldn't it be only natural to talk to them honestly when you see they get hurt by your silence or actions?
Sorry, but I could absolutely not relate to that and many other things Teh did. A lot of his actions seemed selfish to me and at some point I just lost all sympathy for him. To be honest, I didn't want him to end up happily ever after with Oh Aew. Oh Aew surely deserved better.
I'm not saying the entire story was bad, actually the general plot is really good. I just think they overdid it a bit with the drama and heartache. To me that didn't look realistic anymore but rather self-produced by the characters due to lack of honest conversations paired with dumb decisions.

Another issue I have is actually the acting of Billkin as Teh and his facial expressions, especially the crying. The scenes when he cried made me cringe really badly. Those scenes should be emotional, captivate the viewer and make them feel sympathy for the character yet I just wanted to fast forward or skip those scenes completely as they looked too extreme and I could not relate nor connect to it because in my opinion someone other than Teh had way more reason to cry their eyes out.
I think PP did better acting-wise, at least his portrayal of his character looked more authentic to me and actually made me feel sympathy for him. Well, except for one scene that gave me strange vibes because Oh Aew is questioning himself as a male and what he does is really exaggerating. Why did he even have that in his wardrobe? A bit too far fetched and just added to other scenes that failed in trying to show emotions because they went overboard by trying too hard.
Together Billkin and PP/Teh and Oh Aew lacked chemistry in my opinion. For me Oh Aew was a better match with Bas and that's not just based on the fact that Bas is a true friend to Oh Aew.

The music did not stick to my memory, sorry. It wasn't annoying because that would be something I would certainly not forget but that also means it wasn't outstanding nor memorable.

Rewatch value is non-existent for me. Teh as a character was too annoying for me and that's exactly why I decided not to watch IPYTM (season 2 of ITSAY). I read enough about it to know that I would only end up disliking Teh even more. In my opinion Teh's behavior in ITSAY was toxic enough for the relationship between him and Oh Aew.
Overall ITSAY did address some serious topics and I think it's good and important to do that because real life isn't a fluffy rom-com, but the way they did it might not work for everyone or even put some people off.