You just made me even more confuse but it makes sense lol. I thought that last sentence he said wondering if he was dating him or not was for sure meant for Maru as they were taking about him in that moment but like you say it was most prob meant to Doeul and he just kept his friendship with Maru. They really don’t specify or clarify anything about their actual relationship status and that’s what confuses most of us
That’s what I was thinking, the story felt kinda rushed to begin with and the ending was very blend, I totally get that Maybe there were situations the author couldn’t help and I don’t really mind how short it was but at least make it understandable (idk if that the right word to use English isn’t my first language ) like to make that many people Confused...yikes...but also maybe I’m just too dumb to comprehend it all lmao

I'm confused??? People said he ended with both..
But I only saw he ended with the older brother and stayed friends only with the younger brother...???
So where you guys get the "both"...??? Or am I missing something...
Cause all I grasp is...Maru wants to stay as friends because he's afraid of losing his feeling for Yeongwoong and their special friendship even though he really likes him.
Maru wants to be with Yeongwoong forever.
And Yeongwoong never responded to Doeul confession until 3 months later??? like behind the scenes...so they're dating.
Yeongwoong says so himself "whether you mean it or not it doesn't matter anymore" & "Was I supposed to answer him?" it means he didn't reply back to him that quick even though imo 3 months is not really that long to think over but hey they're dating so I'm not the one to judge here X')
Although it's still short enough for him to think about Maru still...after all he's his first crush.
On top of that the last chapter quote Yeongwoong says "I wonder if we're really dating"
I believe this sentence is meant for Doeul and not Maru.
It's the fact Doeul is indifferent about Yeongwoong gets to hang out with his old crush Maru.
And Doeul response to that is "I don't feel that way about you because I see you almost every day"
Yeongwoong feels awkward to that response as if maybe Doeul doesn't enjoy seeing Yeongwoong that often or perhaps a nuisance and changes the topic about haven't seen Maru in a long while.
Doeul leans forward a kiss to reassure him and ask "Does that make you sad?"
Yeongwoong responded is "No, not really.."
I'm sorry for writing a lot...but this is how I see the ending as..(><;;;;