I think if he prays 5 times or not, its between him and God.
Its not that black and white as in case of neighbor or friend. "its b/w them and God" can be said for neighbors and others but not for spouse unless someone's concept of marriage is just to sleep together and on their way in the morning.
Marriage is the foundation of a household/family and both spouses are the pillars of it. What one does really effects other. For example If I get a party freak drinking spouse who loves to drink, chances are that now or later, i'll get into drinking too.