Uncle Antony sure knows how to stick his nose in business where it doesn't belong. Not only does he frequently write to Clarissa to pressure her into obeying her parents, but he offers up his house as a prison for his unfortunate niece. Don't ever trust a guy who has a moat around his home.
Even if he's more crotchety than Oscar the Grouch, Uncle Antony definitely has a soft side. He writes to Mrs. Howe (yes, Anna's mom) to propose to her right in the midst of all of Clarissa's troubles. "I did make a sort of resolution ten years ago never to marry," he starts out his proposal letter (197.6). Maybe the old bachelor is a preview of what Lovelace could be (if he stays away from the ladies, that is). Anyway, karma comes back to bite our favorite bachelor uncle when Mrs. Howe rejects him. Guess that's what happens when you step on your niece's toes!