1. "IF" you prove that "wife has an extra marital relationship", THEN wife is not entitled to any type of maintenance, alimony or whatever BUT you are entitled to Divorce Decree on grounds of Wife's Adultery.
2. You are also advised to immediately file Police FIR on boy-friend of Wife and Wife, for Cheating, Fraud, Mischief, Nuisance, Breach of Trust, Intimidation, Threatening, etc.... and carry on forward from there, in your own futuristic interests. Once you do this progressively, Wife & boyfriend will come down to their knees.
Keep Smiling .... Hemant Agarwal