It is believed that the marriage that will make her permissible for her first husband must be a valid marriage. Temporary marriage (Mut’ah marriage) or marriage for the purpose of making her permissible for first husband (Tahleel marriage) are harams and invalid. i.e. one cannot marry a woman temporarily with an intention to divorce her and make her permissible for her first husband is haram and invalid. Such marriages don’t make a woman permissible for her first husband. Majority of scholars are of same belief and say so.