Now that the cat's almost out the bag, I guess I have to give you the full run down. Adam and Liam both liked each other, yes romantically but had always kept it to themselves. The were both still in their closets and behaved like other normal boys their age. Hanging out with their peers, being super athletic and into sports was their everyday thing. They were so guy-ish and a bit manly that their peers wanted to be like them. Now let me explain their s****l orientation.
Adam was asexual, almost demisexual and a bit aromantic as well. He was the kind of person who was not really attracted to any gender group sexually. In other words s****l attraction was a foreign concept to him and his body. He also had little to zero interest in dating anyone, again regardless of their gender identity or sexuality. He did have two ex-girlfriends though and had also had s*x before, so he wasn't a virgin. Why do I say he's a bit demisexual, well because he is an emotional guy. Once he opens up to the thought of being committed to a romantic relationship with someone, he tends to be a bit romantic and sexuality active. That is how he had managed to get laid in the first place. In short all that mattered to Adam was having a strong and good emotional connection.
Liam was a whole different story from Adam. He was bisexual, leaning more towards gay. Even though he was bisexual, he was more interested in guys for strong and emotional bonds, while sexually he found girls more attractive. That was mainly due to the fact that he had never dated a guy in his life before. Liam had four ex-girlfriends, with all relationships having ended on bad terms. That is how he had come to the conclusion that having 'no strings attached' fun s*x with girls was the way out for him. He had his fair share of male crushes which he never dared to say out loud, even to his diary in fear of being found out.
Liam had liked Adam from the very first time he had laid eyes on him, much like Camila had. Meaning he had felt that way for over ten years, back when they first met in elementary school. Adam had just transferred to his school and Liam approached him first since he was the quiet new transfer kid and that's how they became friends. Unlike Camila, Liam was satisfied with having Adam happy by his side more than anything, hence they were still best friends despite his feelings.
How Adam came to like Liam though is a pretty common story. It was on one rainy day and it was pouring like crazy, like rent was due or something (for the clouds). The rain started falling even harder once it was time to go home. Oh, all this happened back in tenth grade, a few months back as they were in eleventh grade when Camila bulldozed herself into the picture. Adam didn't have an umbrella on him and was left stranded needing help, even though he didn't want to call anyone to ask for it. Liam came out and saw him standing by the entrance, looking at his phone dreadfully and summed everything up. He took Adam's phone and shoved it into his (Adam's) backpack, covered them both with his blazer, pulled him close (with his arm around Adam's shoulders) and charged out the school. Liam's Dad was actually going pick him up, plus he had an umbrella in his bag, but he chose to run through the rain with Adam instead. That won him some brownie points as that's when and how Adam came to have feelings for him, began to like him.