Is it cruel to make your pet wear clothes?

No, I don't think its anymore cruel than all those times when you were a baby and your folks would make you wear those awful one piece suits or costumes with bunny ears or tail. Parents did it for their own amusement and I get the same joy out of putting a hideous Christmas sweater on Oscar in Decemeber- just to see him react while trying to pull it off.

Any kind of scarf or ribbon around the neck is a big fat NO though.