Complex sentence: Gerald leaves for Spain insisting that Carrington run off with him, she refuses but they continue the relationship until they get caught by Ralph, Lytton manages to avoid the break-up and secretly aids the couple to continue their affair until it ends by itself.
Split into simpler sentences: Gerald leaves for Spain insisting that Carrington run off with him. She refuses but they continue the relationship until they get caught by Ralph, Lytton manages to avoid the break-up and secretly aids the couple to continue their affair until it ends by itself.