It's cute and fluffy, plus no real third parties involved... Just that they're both afraid to tip off the status quo until one discovers a concrete proof that he could be into him too (jerking off of his suit).. It's just light and didn't take them too long after that incident to settle down. I wish I've seen more of Suga's POV as a middle/high schooler though, because he was the first to have sex with other people, yet in the beginning, he made it seem as if he was the one left behind.
Tomodachi Ijou no Koto, Shitai.