Big stomach : the moment you look pregnant as a man you know that you are being fed wrong food or you have become so lazy and let your woman do all the work all of which means she is fed up with you
Long nails : Nothing gives away that the wife has stopped caring like long nails on a man. For some funny reason most guys seem to want to be reminded of simple things when they get married, it seems they give away all their right to think when they say I do, especially when it comes to grooming. So if his nails are long, she has checked out
Wearing ankle socks with formal pants and shoes: The moment he sits down and you can see part of his un-lotioned feet know that she is having discussions with her best friends about how useless he is. Normally cheaters are let, to go to work looking like this so they can be less attractive
Badly ironed pants: If she lets you leave home like a cow just chewed your pants it means you have not been bringing your salary home. Chances are she feels you don't deserve the benefits of ironed pants as that is a waste of electricity which you don't pay
Unattractive lunch box : have seen some guys who are married with lunch boxes like dishes from eliminated top chef contestants. You can see there was no effort nor love from this. If your lunch box still include white bread and polony, run because she is trying to kill you. You might also want to check if she has taken a funeral cover in your name
Poorly maintained teeth : this already says there is no love making because chances are the breath already smells like garbage so no kissing is happening
Poor performance at work: people with happy wives excel at work, they have the necessary support, nutrition and inspiration to give their best
Unpolished shoes : if your shoes look like you have just done rounds at the field she is so over you. Dirty shoes also ends up making your pants dirty
NB: if you are contributing towards house chores, declaring your salary, not cheating and surprising her with gifts randomly yet the above applies to you, get marriage counselling; you are being abused.

op your first point got me laughing.
Honestly i dont think a man with a big stomach means he is not happy in his marital abored.
The signs of a man that is not happily married are:
1.Coming home late from work: Its only an unhappy husband that will stay back late even after office hours just to have fun before going home to his wife. a man that is happy with his marriage will always want to go home just to be with his wife.
2.LACK OF WORK CONCENTRATION: Any man that is not happy maritally tends to loose focus in his work place because of mental and emotional sadness in regards to his marriage.
3.ANGER TO HIS WIFE.
when a man shout at his wife even if she does nothing wrong to him. it means he is unhappy with the marriage.

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lalasticlala. let us go there

This is sadly true for some men.