WTF! My uncle slapped his wife twice for denying him sex on a Sunday!

My Uncle had a mild Argument with his new wife and ended up slapping her twice because she denied him sex yet again after several months of denying him sex most especially on Sundays.
He hardly has time or strength to have sex during week days because of the tiresome nature of his work. Most Saturdays if he asks for it, the wife always complains of being tired for sex after Saturday house chores, then on Sunday that both of them are free to have fun, the wife still thinks its inappropriate to have sex before going to church.
Is there anything wrong in having sex with your wife or husband before going to church service