There are similarities in all cases, but nothing is black/white.
My H (in MLC for 2.75 years) has never left our home. To my knowledge, there is no OW. He fantasizes about life he doesn't have. He has said he is "done" since 1/09, but has never left our home. Still does family things....not couple things.
His replay was concerts, being a workaholic, secret drinking, excessive exercise, teen type movies, slang, wanting to run.
So, I have always considered him a "runner" with low energy, so he doesn't actually leave the situation.