Not Quite Right

So in this ever so long hiatus, I've been wondering about this Sydney/Vaughn dilemna... how Vaughn isn't really Vaughn, and he's been hiding this huge secret from Sydney for as long as he's known her.

Something isn't sitting well with me... during the whole Season 3 ordeal with the Syd/Vaughn/Lauren love trinagle, and the Vaughn & Lauren parallelisms to Jack & Irena, Vaughn was portrayed as the betrayed husband. We saw his anger towards Lauren at the end of Season 3, and just how much he was affected emotionally in the beginning of Season 4 ("Ice"). However, now we find out, he was doing the exact same thing to Sydney the whole time... we'd like to think that Vaughn really does love Sydney, however, after he found out that his wife was actually a double agent, cheating on her husband and her country, it would make sense that Vaughn would realize how much it hurts to be lied to, and tell Syd the truth right away. Why did it take more than a season from Vaughn finding out about Lauren to Vaughn confessing to Sydney?

Hopefully we'll get an answer to this... 37 days and counting!