he wants to leave but he is having severe anxiety- poor kid-
Oh wait- you said this is a MAN- ???
REAL MEN COPE/SUCK IT UP.
No one can make him unhappy- he DECIDES to be happy wherever he is and whomever he is with.
a friend would suggest to a real MAN to act right and recommit himself to his ENTIRE family- and if you are friend- I don't know why you are not telling him that-
If he decides to leave though, being so self- centered, his wife is only losing a man that was not much of an asset anyways-
From reading your post I would think that he really would like his marriage to work perhaps he is using staying 'because of his daughter' as an excuse, he is right it would not help his daughter for her parents to split up, a marriage is always worth saving, as a friend maybe you could advise them to seek more help and simply make an effort to adjust to each others needs.If he really needs to leave he should wait till his daughter is an adult, 18 its okay if he is miserable he is the one who wants out, his daughter does not deserve to be miserable ,she didnt do anything.and if given a choice would want her Dad to stay.
Yes, this is what parents do. It's more than "fair", it's the right thing to do for this girl.
Even if they wait for a year or so it will still be extremely painful for her and might send her into a depression or major anxiety.
Why would you think it's not "fair" for him to decide to stay for the sake of his daughter? Not "fair" to who?