The Bible frequently uses adultery and prostitution as a metaphor to describe Israel's worshipping of false gods. Yet we know God has repeatedly forgiven those who came back to him and abandoned their idols.
In Canon Law, the victimized spouse of one who has committed adultery has the right
to sever common conjugal life (although the bond of marriage remains intact).
Can. 1152 §1 It is earnestly recommended that a spouse, motivated by christian charity and solicitous for the good of the family, should not refuse to pardon an adulterous partner and should not sunder the conjugal life. Nevertheless, if that spouse has not either expressly or tacitly condoned the other's fault, he or she has the right to sever the common conjugal life, provided he or she has not consented to the adultery, nor been the cause of it, nor also committed adultery.
Therefore, although the Church recommends earnestly that forgiveness prevail, adultery is serious enough that the victimized, innocent spouse is permitted to separate.