Michael is saying what Jake would say if he wasn't as nice as he was or as used to Brett cheating on him. Michael asks Cohn "Is Robert Cohn going to follow Brett around like a steer all the time?"(146). As Michael is bashing on Cohn Jake makes no attempt to stop him from doing so, which reenforces that Jake didn't think what Michael was saying was inappropriate. Later Mike says that Jake should tell Cohn that he should behave or leave, Jake replies, "Yes, it would be nice for me to tell him"(148). This is like Jake saying that it would be nice to tell Cohn to behave, which in Jakes case, because he truly loves Brett and would prefer Cohn to stay away, would be more like ripping into him like Mike did.