In most of the comments, Dan is simply portrayed as air, as if he doesn't exist physically or mentally.
- Lester will and should move into the house they share (Sarah and Dan's).
- Lester is simply meant to evict Dan from his own home
- Lester is destined to destroy his family, take away his wife and children ...
and so on and so forth...
It may be that Dan tends to be a ‘cuckold’, it may be that he likes to share his wife with other men chosen ‘together’
and finds fulfilment in that.
But the fact that he leaves the field - especially his family, children and home - to Lester or someone else so ‘without resistance’, so without a fight, has nothing to do with ‘sharing and fantasy’, because this is about his, ‘Dan's’, existence.
He may have lost some of his security and mental strength through the loss of his job, but he is not completely lost.
Sooner or later, he will pick himself up again and regain his security and strength.
And I am convinced that he will emerge stronger from this situation.
(which seems hopeless for him at the moment, because everything is in Lester's favour).
He will carry out his campaign of revenge powerfully and mercilessly, with or without Sarah.
But I assume that Sarah will stand by his side because she is clever, because she loves him, because she is his wife and
he 'Dan" is the father of her - their - children, and because she will ultimately never put LUST (Lester) before LOVE
(Dan and the family)...