Is it a must for the father to give maintenence fee to the wife is she apply? (In this case, the guy did not do wrong. Theres conflict between both families and both did not do wrong)

It depends on how the judge rules during the hearing. If the judge favours the that a maintenance fee is needed the refusal to pay could result in even jail time. Found this on the law society of Singapore page. "The Judge has the power to impose a fine or even sentence your husband/ex-husband to imprisonment for a term of not more than one month for each month that he is in arrears of maintenance."

thanks