And he's almost always been willing to sacrifice Sydney's happiness . . . even for that of people who don't mean one-tenth as much to him. People who aren't his wife . . . Hm.
What would really "suck" is if Sydney let him put her through all that and just turned around and immediately forgave him and said, "Here, let me drop everything and forget all you put me through and forgive you this second because after all you were married to her, how could you guess that she was an evil witch? Let me comfort you. Come to bed, Dear!" Jack's still paying for his mistakes over 30 years later. The least Vaughn can do is pay for his for a couple of weeks.