Dramatic irony in Of Mice and Men

The major irony in Of Mice and Men is that George kills Lennie because of their friendship. George kills Lennie to spare him from a worse death. George complained about Lennie and his defects, but realizes his importance only after his death. Once Lennie is dead, George loses the weight of responsibility Lennie caused him, but he is also lonely. Also, Lennie and George's dream to own their own farm that is carried out throughout the novel dissapears with Lennie's death.
George and Lennie dream of owning a little farm of ten acres with a windmill, a little shack, an orchard and many animal…