I think the beginning of the story established that little bro keeps things from bigger bro.
Like big bro knows he was going through his ho phase, but it wasn't info directly from little bro.
Yee I just think big bro gotta put more effort in to get to know what’s going on with his brother more. Like no shot he thinks the whole abandonment arc was just over and done with a few apologizes. It’s obvious smth is going on in the MC’s life and like outta the two even as the omega bro lived a better life with a rich family compared to Mc (saw someone point this out in the comments and I thought it was a good point)
Lmao hit the brother I think the drama would be cool for that. The brother never once checked up on MC (in them living together) when he looked distraught maybe a simple yo what’s wrong but never persisted him for an answer and made him feel safe after the whole ‘abandonment I’m doing this for both of us tho’ arc