I think it's just as well we've discovered this flaw in temperament of yours at an early stage because now that we know about it we can be sure that we won't place you in a situation in which you"ll lose control.".
Simmonds, ironically when faced with the overwhelming calamity of the death of Kenny becomes insecure and panicked. It's extremely ironic to the conversation in Act 1 where Simmonds is taking the role of the in control mentor who assumes an "I know what's best" position. When the two realise that they have indeed killed Kenny, Ross is the one who tries to find a way out. Simmonds, scared and totally incompetent, remarks, "I"m not helping anybody, boy. You did it!" abandoning his fatherly figure. It seems extremely ironic and shocking how, Ross, who has just beaten Kenny to death, almost systematically turns to attack Simmonds, his apparent "workmate". The play ends with Ross and Simmonds attacking each other in a "frenzied ritual of exorcism". .
Another shocking reminder of the illusion of mateship is where Kenny, Simmonds and Ross have gathered around to enjoy a beer, only minutes after Ross's horrifying bashing of Kenny. Kenny, battered and bruised, laughs and joins in an apparently friendly conversation. Here Kenny and Simmonds, ironically like old mates, jovially question Ross's quick temper and his innocence about prostitutes. .
Another less obvious example of mateship is the idea of sisterhood. The two sisters in the play, Kate and Fiona, are introduced after walking into the police station to report an offence. These two reflect the same leader-and-led relationship of Simmonds and Ross which is evident in the early part of the play. The elder sister, Kate, is the one who reports the offence, even though it's about the other's husband who has allegedly beaten Fiona. Throughout the conversation, Kate is the one who converses. The two couples are deeply parallelled in that both Kate and Simmonds are the ones who direct their conversations as opposed to their apparently weaker partners.