Responsa for Yevamot 169:4

Q. Rabbi Eliezer B. Joseph betrothed L through a deputy. Subsequently it was discovered that at the time of the betrothal L was pregnant through harlotry.
A. If L refuses to accept a divorce, Rabbi Eliezer is permitted to marry another woman. Rabbenu Gershom had intended that his prohibition against bigamy should apply only when the first marriage was legitimately contracted; but he had not intended to protect by his takkanah the marriage of a loose and immoral woman. Those who impute such intentions to Rabbenu Gershom will receive severe punishment from Heaven for defaming this saint's character and malignantly ascribing to him silly ordinances in order to make him appear ridiculous and thus discredit his other takkanot. Thus, the Rabbis are intent upon breaking up the marriage of a man to a woman pregnant by another. Would, then, Rabbenu Gershom protect such a marriage by his takkanah! I am even inclined to the opinion that the betrothal itself was invalid since the bridegroom was ignorant of facts, the knowledge of which would have prevented him from marrying L. There is no doubt, however, that Rabbi Eliezer is permitted to marry another woman in case L refuses to accept a divorce.
SOURCES: Cr. 161.

Q. While A was absent in a foreign country, his wife borrowed money for her sustenance. Upon his return, A refused to pay his wife's debts claiming that she could have supported herself by her work.
A. Biblical law requires that a husband must provide his wife's sustenance; therefore, A must pay whatever his wife borrowed for her sustenance.
SOURCES: Pr. 232; L. 383. Cf. P. 11; Mord. Ket. 273.