I couldn’t even understand their friendship or how it had survived all our bullshit over the years.
Another contrast to Maddox - Maddox understands (believes?) that true friendship transcends other things, whereas Devon doesn't understand that. This also shows that Devon has low self-esteem - he believes that he would be the cause of his brother and his brother's best friend ending their friendship; Maddox knows that this won't happen and that the brothers don't live up to some code of masculinity that Devon seems to ascribe to.
