Everything is subtext with Charles’s father. Dry, sarcastic, and slightly mean subtext, but still. He’s not around for many scenes in the novel, but his interactions with Charles are some of the novel’s most memorable, and certainly most comic. Mr. Ryder spends most of his time reading alone in the library. We know he’s a hermit because he made sure to "get rid of" Charles’s Aunt Phillipa and because he seems to aim at getting rid of Charles as well. When he does emerge, it is for the purposes of eating formal dinners and taunting other people for his own amusement.
Despite these misanthropic characteristics, Mr. Ryder is far from dislikable and certainly no villain. On the contrary, he’s more harmlessly amusing than anything else. In fact, the best way to think of Mr. Ryder is as a 1920s version of Dr. House. He’s self-centered, gruff, and mocking – but he’s hilarious and we all love him anyway.
Mr. Ryder allows for some great comparisons between Charles’s home life and Sebastian’s. While Sebastian has been utterly babied to death, Charles’s father doesn’t even care if he stays at Oxford or leaves:
"Then you agree to my leaving Oxford?"
"Agree? Agree? My dear boy, you're twenty-two."
"Twenty," I said, "twenty-one in October."
"Is that all? It seems much longer."
Sebastian can’t seem to escape his family; Charles isn’t even wanted at home. Sebastian greets his father with a kiss, and Charles notes that he himself "has not kissed [his] father since [he] left the nursery." The more we see of Sebastian’s family, the more we are aware of the fundamental differences between his and Charles’s upbringing.