'Committing Adultery' in the Bible

That sayest - Do not commit adultery! Art thou, committing adultery? That abhorrest sacrilege, Art thou, robbing temples?

So, if she lives with another man while her husband is still alive, she will be called an adulteress [i.e., a person who is sexually unfaithful to their mate]. But if her husband dies, she is legally free to marry another man without committing adultery.