i agree with like, that whole theory you have going on. except I think ryan did something to really make brendon feel like he was totally useless and out of the question.
like, for example, all the time ryan spends with jon, i think brendon got it into his head that ryan developed feelings for jon. and brendon is all, whyhowwhat what did i do, how could you not be fine with ryanandbrendon but be totally okay with ryanandjon?

only, ryan doesn't realize this is what brendon is thinking, and continues on hanging out with jon for support.

or something.

idek, i have so many theories.